Patent Publication Number: US-2022230044-A1

Title: Di capacitive embedded metal card

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 15/928,813, filed Mar. 22, 2018 (status: allowed), which claims priority from U.S. Provisional Application Ser. No. 62/623,936, titled DI CAPACITIVE EMBEDDED METAL CARD, filed Jan. 30, 2018, incorporated by reference herein in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     Cards, such as identification cards, transponder cards, and transaction cards, such as credit cards, debit cards, sometimes referred to as smart cards, are well known in the art, some embodiments of which may comprise one or more metal layers. An exemplary such card is shown in U.S. Pat. No. 8,725,589, incorporated herein by reference. It is also well known to embed a microchip or payment module in transaction cards, including in metal cards. Some embedded payment modules, referred to as “dual interface” modules, have contacts disposed on one side of the card and configured to interface with a card reader, and a radio frequency identification (RFID) antenna for communicating inductively with a card reader. In a metal environment, such as a metal card, it may be necessary to provide a booster antenna or amplifier to improve performance of the communication interface with the card reader. 
     In particular, it is known to use the metal frame of the card itself as such an antenna or amplifier, with the metal enclosure that surrounds the payment module chip having a discontinuity or “slit” in the metal. U.S. Pat. No. 8,608,082 (&#39;082 patent) to Le Garrec et al. and U.S. Pat. No. 9,812,782 (and others), to Finn et al., incorporated herein by reference, disclose metal cards with such a discontinuity in the form of a slit emanating from a mounting location of the RFID chip in the card to a peripheral edge of the card. The concept of a metal, card-shaped, non-contact antenna having a slit, for RFID signal amplification in a metal environment, is also described generally in the literature, such as at “A Metallic RFID Tag Design for Steel-Bar and Wire-Rod Management Application in the Steel Industry,”  Progress In Electromagnetics Research  ( PIER ) Vol. 91 (2009). 
     The &#39;082 patent characterizes the metal frame of the card as an amplifier for amplifying the gain of the near-field communication antenna electrically connected to the microcircuit associated with the payment module, the amplifier comprising “an electrically conductive element electrically insulated from the microcircuit and from the antenna, of generally annular shape,” which in some embodiments forms a ring that is broken at least once. 
     The Finn patents refer to the payment module as a “transponder chip module (TCM) comprising an RFID chip (IC) and a module antenna” and describes the amplifier formed by the card body as a “coupling frame” having “an electrical discontinuity comprising a slit or non-conductive stripe.” 
     Regardless of the nomenclature used, metal “slit” cards may have some disadvantages. In particular, embodiments in which a single slit extends from a midpoint of one edge of the module pocket to the periphery of the card in a straight horizontal line that is the shortest path from the pocket to the periphery provides little resistance to flexure of the card at the discontinuity. Metal cards may still have one or more layers over the metal layer. For a card in which the one or more layers is plastic, the plastic may start to wear or whiten because of such flexure. Thus, there is a need in the art for designs that provide better resistance to card flexure and the potential wear induced thereby. Although Finn proposes some alternative constructions, there is still a need in the art for constructions that provide improved functionality and aesthetics. 
     SUMMARY OF THE INVENTION 
     One aspect of the invention comprises a transaction card comprising a metal layer, an opening in the metal layer to receive a transponder chip module, and at least one discontinuity. The discontinuity comprises a gap extending from a front surface of to a back surface of the metal layer and having a width. The discontinuity extends from an origin on the card periphery to a terminus in the opening for the transponder chip. The card has a greater resistance to flexure than a card having a discontinuity of the same gap width in which the terminus and the origin are the same distance from a line defined by a first long side of the card periphery in an absence of one or more strengthening features. One strengthening feature comprises a single discontinuity wherein one of the terminus or the origin are located relatively closer to the first long side of the periphery than the other. Another strengthening feature comprises a plurality of discontinuities, each having a length, wherein fewer than all of the plurality of discontinuities extend from the card periphery to the opening. Another strengthening feature comprises a self-supporting non-metal layer disposed on at least one surface of the card. Still another strengthening feature comprises one or more ceramic reinforcing tabs disposed on one or both surfaces of the card, surrounding the opening. The card may have one or any combination of the foregoing strengthening features. 
     In general, the opening in the metal layer has a first edge parallel and relatively closest to a first short side of the card periphery and aligned with a first portion of the card periphery. A second edge of the opening is parallel and relatively closest to a first long side of the periphery. A third edge of the opening is parallel and relatively closest to a second long side of the periphery. The first edge of the opening is relatively closer to the short side of the periphery than the second edge is to the long side of the periphery. The second edge of the opening is relatively closer to the first long side of the periphery than the third edge is to the second long side of the card periphery. The edges of the opening define corners. The opening may be a stepped opening having a first open area defined in the first surface of the card and a second open area defined in the second surface of the card, wherein the first open area is greater than the second open area. 
     Another aspect of the invention comprises a transaction card having a metal layer, an opening in the metal layer, and a discontinuity, wherein the discontinuity defines a path from in which one of the terminus or the origin are located relatively closer to the first long side of the periphery than the other. 
     In some embodiments, the short side of the card periphery has a region aligned with the first edge of the opening, and the origin is located on the periphery outside the aligned region. The terminus may be located at the one corner of the opening, or relatively closer to one corner than to an adjacent corner defined by a common edge. 
     In some embodiments, the path of the discontinuity comprises at least two changes in direction of 90 degrees or more. At least a portion of the path of the discontinuity may define a stairstep geometry comprising more than two changes in direction of 90 degrees, or a portion of the path of the discontinuity may define a sawtooth geometry comprising more than two changes in direction of more than 90 degrees, or a combination thereof. In embodiments wherein the path of the discontinuity comprises at least one change in direction of more than 90 degrees and at least one change in direction of 90 degrees, the path may have a micro stairstep geometry and a macro sawtooth geometry, comprising at least a first plurality of more than two changes in direction of 90 degrees leading to a first change in direction of more than 90 degrees and a second plurality of more than two changes in direction of 90 degrees leading to a second change in direction of more than 90 degrees. Discontinuities with a stairstep geometry may have a rise greater than the run, or vice versa. Discontinuities with a stairstep geometry may have a curved radius at each change of direction. 
     In some embodiments, the path of the discontinuity has at least one section of curved geometry, including embodiments in which the path of the discontinuity has one or more changes in direction greater than or equal to 90 degrees, wherein at least one change in direction has a curved geometry. The discontinuity may have, for example, a sinusoidal shape comprising at least two changes in direction of more than 90 degrees. 
     The discontinuity may extend from the first short side of the periphery to the second edge of the opening or from the first or second long side of the periphery to the opening. The first and second edges of the opening may be said to define a first corner of the opening and the first and third edges of the opening to define a second corner of the opening. In some embodiments, the discontinuity extends from the first edge in a location relatively closer to the second corner than the first corner and terminates in the short side of the periphery in a location relatively closer to the first corner than the second corner. In other embodiments, the discontinuity extends from the opening in a location relatively closer to the first corner than the second corner and terminates in the short side of the periphery in a location relatively closer to the first corner than the second corner. 
     The card may comprise a transponder chip module disposed in the opening, in which case the metal layer comprises a booster antenna or amplifier for the transponder chip module. The card may have a first non-metal layer, such as a plastic or ceramic layer, disposed on a first surface of the metal layer. A ceramic layer may comprise a ceramic coating wherein the gap defined by the discontinuity is at least partially filled with the ceramic coating. The non-metal layer may comprise a decorative layer comprising one of wood or leather. A second non-metal layer may be disposed on a second surface of the metal layer. In one embodiment, the first non-metal layer comprises a ceramic layer and the second non-metal layer comprises a plastic layer. The discontinuity may be optically visible from one or both surfaces of the card, or may not be optically visible from at least one surface of the card. 
     Another aspect of the invention comprises a transaction card comprising a metal layer having an front surface and a back surface; and a plurality of discontinuities in the metal layer wherein fewer than all of the plurality of discontinuities extend from the periphery to the opening. At least one of the plurality of discontinuities may have a length equal to a shortest length from the opening to the periphery. At least two of the plurality of discontinuities may be parallel to one another. 
     Another aspect of the invention is a method for making a transaction card as described herein. The method comprises providing the metal layer, creating the opening in the metal layer sized to accommodate the transponder chip module, and creating the discontinuity, wherein one of the terminus or the origin is located relatively closer to the long side of the periphery than the other, and disposing the transponder chip module in the opening. The discontinuity may be formed prior to creating the opening for the transponder chip module. The method may comprise creating the one or more discontinuities having an endpoint located inside the boundary of the opening. The method may comprise creating a stepped opening having a first portion with a first open area, and a second portion having a second open area greater than the first open area. The method may comprise creating the first portion of the opening from the front surface of the card, and creating the second portion of the opening from the back surface of the card. The discontinuity may be formed using a laser. The method may further comprise at least partially filling the gap defined by the discontinuity with a non-metal material. At least one non-metal layer may be disposed on the front surface or the back surface of the metal layer, such as by adhesive bonding, or wherein the non-metal layer comprises a ceramic layer, by spray coating the ceramic layer onto the metal layer. Spray coating the ceramic layer onto the metal layer may comprise at least partially filling the gap with the ceramic coating. 
     Another aspect of the invention may comprising providing a card as described herein having a non-metal layer comprising a ceramic layer having a color, further comprising creating with a laser one or more permanent markings on the ceramic layer having a different color than the ceramic layer color. Creating the one or more permanent markings on the ceramic layer may comprise removing an overlying ceramic layer to reveal an underlying layer having a different color, which the underlying layer may be the metal layer or an underlying ceramic layer having a different color than an outermost ceramic layer. 
     Another aspect of the invention comprises a card having a metal layer as described herein, having at least one non-metal layer comprising a self-supporting layer, such as a self-supporting layer comprising polyimide or a fiberglass reinforced layer comprising an epoxy, such as FR4. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a schematic view illustration of a machine tool path for creating a discontinuity in a metal layer relative to boundaries of upper and lower portions of a transponder chip opening in the metal layer. 
         FIG. 1B  is a perspective view illustration of a metal layer created in accordance with  FIG. 1A , viewed from the front, upper, right side, showing the opening and discontinuity prior to insertion of a transponder chip into the transponder chip opening. 
         FIG. 1C  is a perspective view illustration of the exemplary metal layer of a card having the discontinuity and opening as depicted in  FIG. 1B , after insertion of the payment module. 
         FIG. 2  is a plan view illustration of the front surface of the card of  FIG. 1C . 
         FIG. 3  is a plan view illustration of the left side of the card of  FIG. 1C . 
         FIG. 4  is a plan view illustration of the right side of the card of  FIG. 1C . 
         FIG. 5  is a plan view illustration of the top side of the card of  FIG. 1C . 
         FIG. 6  is a plan view illustration of the bottom side of the card of  FIG. 1C . 
         FIG. 7  is a plan view illustration of the back surface of the card of  FIG. 1C . 
         FIG. 8A  is a schematic view illustration of a machine tool path for a discontinuity relative to boundaries of upper and lower portions of the transponder chip opening for another exemplary card embodiment. 
         FIGS. 8B-8F  are perspective and plan view illustrations of the front surface, top side, left side, back surface, respectively, of an exemplary card having the discontinuity depicted in  FIG. 8A . 
         FIG. 9A  is a schematic view illustration of a machine tool path for a discontinuity having a stairstep geometry relative to boundaries of upper and lower portions of the transponder chip opening for another exemplary card embodiment. 
         FIGS. 9B-9F  are perspective and plan view illustrations of the front surface, top side, left side, back surface, respectively, of an exemplary card having the discontinuity depicted in  FIG. 9A . 
         FIG. 10A  is a schematic view illustration of a machine tool path for a discontinuity having a curved geometry relative to boundaries of upper and lower portions of the transponder chip opening for another exemplary card embodiment. 
         FIGS. 10B-10F  are perspective and plan view illustrations of the front surface, top side, left side, back surface, respectively, of an exemplary card having the discontinuity depicted in  FIG. 10A . 
         FIG. 11A  is a schematic view illustration of a machine tool path for a discontinuity having a sawtooth geometry relative to boundaries of upper and lower portions of the transponder chip opening for another exemplary card embodiment. 
         FIGS. 11B-11F  are perspective and plan view illustrations of the front surface, top side, left side, back surface, respectively, of an exemplary card having the discontinuity depicted in  FIG. 11A . 
         FIG. 12A  is a schematic view illustration of a machine tool path for a discontinuity having a micro stairstep and macro sawtooth geometry relative to boundaries of upper and lower portions of the transponder chip opening for another exemplary card embodiment. 
         FIGS. 12B-12F  are a perspective view (B) and plan view illustrations of the front surface (C), top side (D), left side (E), and back surface (F), respectively, of an exemplary card having the discontinuity depicted in  FIG. 12A . 
         FIG. 13A  is a schematic view illustration of a machine tool path for a discontinuity having a sawtooth geometry relative to boundaries of upper and lower portions of the transponder chip opening for another exemplary card embodiment. 
         FIGS. 13B-13F  are a perspective view (B) and plan view illustrations of the front surface (C), top side (D), left side (E), and back surface (F), respectively, of an exemplary card having the discontinuity depicted in  FIG. 13A . 
         FIG. 14A  is a schematic view illustration of a machine tool path for a discontinuity having a curved sinusoidal geometry relative to boundaries of upper and lower portions of the transponder chip opening for another exemplary card embodiment. 
         FIGS. 14B-14F  are a perspective view (B) and plan view illustrations of the front surface (C), top side (D), left side (E), and back surface (F), respectively, of an exemplary card having the discontinuity depicted in  FIG. 14A . 
         FIG. 15A  is a schematic view illustration of a machine tool path for a discontinuity having a curved sinusoidal geometry relative to boundaries of upper and lower portions of the transponder chip opening for another exemplary card embodiment. 
         FIGS. 15B-15F  are a perspective view (B) and plan view illustrations of the front surface (C), top side (D), left side (E), and back surface (F), respectively, of an exemplary card having the discontinuity depicted in  FIG. 15A . 
         FIG. 16A  is a schematic view illustration of a machine tool path for a discontinuity having a curved sinusoidal geometry relative to boundaries of upper and lower portions of the transponder chip opening for another exemplary card embodiment. 
         FIGS. 16B-16F  are a perspective view (B) and plan view illustrations of the front surface (C), top side (D), left side (E), and back surface (F), respectively, of an exemplary card having the discontinuity depicted in  FIG. 16A . 
         FIG. 17A  is a schematic view illustration of a machine tool path for a discontinuity having a curved sinusoidal geometry relative to boundaries of upper and lower portions of the transponder chip opening for another exemplary card embodiment. 
         FIGS. 17B-17F  are a perspective view (B) and plan view illustrations of the front surface (C), top side (D), left side (E), and back surface (F), respectively, of an exemplary card having the discontinuity depicted in  FIG. 17A . 
         FIG. 18A  is a schematic view illustration of a machine tool path for a discontinuity having a curved sinusoidal geometry relative to boundaries of upper and lower portions of the transponder chip opening for another exemplary card embodiment. 
         FIGS. 18B-18F  are a perspective view (B) and plan view illustrations of the front surface (C), top side (D), left side (E), and back surface (F), respectively, of an exemplary card having the discontinuity depicted in  FIG. 18A . 
         FIG. 19A  is a schematic view illustration of a machine tool path for a discontinuity having a stairstep geometry relative to boundaries of upper and lower portions of the transponder chip opening for another exemplary card embodiment. 
         FIGS. 19B-19F  are a perspective view (B) and plan view illustrations of the front surface (C), top side (D), left side (E), and back surface (F), respectively, of an exemplary card having the discontinuity depicted in  FIG. 19A . 
         FIG. 20A  is a schematic view illustration of a machine tool path for a discontinuity having a single stairstep geometry relative to boundaries of upper and lower portions of the transponder chip opening for another exemplary card embodiment. 
         FIGS. 20B-20F  are a perspective view (B) and plan view illustrations of the front surface (C), top side (D), left side (E), and back surface (F), respectively, of an exemplary card having the discontinuity depicted in  FIG. 20A . 
         FIG. 21A  is a schematic view illustration of a machine tool path for a discontinuity having a single stairstep geometry relative to boundaries of upper and lower portions of the transponder chip opening for another exemplary card embodiment. 
         FIGS. 21B-21F  are a perspective view (B) and plan view illustrations of the front surface (C), top side (D), left side (E), and back surface (F), respectively, of an exemplary card having the discontinuity depicted in  FIG. 21A . 
         FIG. 22A  is a schematic view illustration of a machine tool path for a discontinuity, which extends from the opening to a bottom side of the card, relative to boundaries of upper and lower portions of the transponder chip opening for another exemplary card embodiment. 
         FIGS. 22B-22F  are a perspective view (B) and plan view illustrations of the front surface (C), bottom side (D), left side (E), and back surface (F), respectively, of an exemplary card having the discontinuity depicted in  FIG. 21A . 
         FIG. 23A  is a schematic view illustration of a machine tool path for a discontinuity, which extends diagonally from the opening to near a bottom left corner of the card, relative to boundaries of upper and lower portions of the transponder chip opening for another exemplary card embodiment. 
         FIGS. 23B-23F  are a perspective view (B) and plan view illustrations of the front surface (C), top side (D), left side (E), and back surface (F), respectively, of an exemplary card having the discontinuity depicted in  FIG. 23A . 
         FIG. 24A  is a schematic view illustration of a machine tool path for a discontinuity, which also extends diagonally from the opening to near a bottom lefthand corner of the card, relative to boundaries of upper and lower portions of the transponder chip opening for another exemplary card embodiment. 
         FIGS. 24B-24F  are a perspective view (B) and plan view illustrations of the front surface (C), top side (D), left side (E), and back surface (F), respectively, of an exemplary card having the discontinuity depicted in  FIG. 24A . 
         FIG. 25A  is a schematic view illustration of a machine tool path for a plurality of discontinuities relative to boundaries of upper and lower portions of the transponder chip opening for another exemplary card embodiment. 
         FIGS. 25B-25F  are a perspective view (B) and plan view illustrations of the front surface (C), top side (D), left side (E), and back surface (F), respectively, of an exemplary card having the discontinuity depicted in  FIG. 25A . 
         FIG. 26A  is a schematic view illustration of a machine tool path for a plurality of discontinuities relative to boundaries of upper and lower portions of the transponder chip opening for another exemplary card embodiment. 
         FIGS. 26B-26F  are a perspective view (B) and plan view illustrations of the front surface (C), top side (D), left side (E), and back surface (F), respectively, of an exemplary card having the discontinuity depicted in  FIG. 26A . 
         FIG. 27A  is a schematic view illustration of a machine tool path for a plurality of discontinuities relative to boundaries of upper and lower portions of the transponder chip opening for another exemplary card embodiment. 
         FIGS. 27B-27F  are a perspective view (B) and plan view illustrations of the front surface (C), top side (D), left side (E), and back surface (F), respectively, of an exemplary card having the discontinuity depicted in  FIG. 27A . 
         FIG. 28A  is a schematic view illustration of a machine tool path for a plurality of discontinuities relative to boundaries of upper and lower portions of the transponder chip opening for another exemplary card embodiment. 
         FIGS. 28B-28F  are a perspective view (B) and plan view illustrations of the front surface (C), top side (D), left side (E), and back surface (F), respectively, of an exemplary card having the discontinuity depicted in  FIG. 28A . 
         FIG. 29A  is a schematic view illustration of a machine tool path for an exemplary discontinuity relative to boundaries of upper and lower portions of the transponder chip opening for another exemplary card embodiment. 
         FIGS. 29B-29F  are a perspective view (B) and plan view illustrations of the front surface (C), top side (D), left side (E), and back surface (F), respectively, of an exemplary card having the discontinuity depicted in  FIG. 29A . 
         FIG. 30A  is a schematic view illustration of a machine tool path for an exemplary discontinuity, having a curved geometry, relative to boundaries of upper and lower portions of the transponder chip opening for another exemplary card embodiment. 
         FIGS. 30B-30F  are a perspective view (B) and plan view illustrations of the front surface (C), top side (D), left side (E), and back surface (F), respectively, of an exemplary card having the discontinuity depicted in  FIG. 30A . 
         FIG. 31A  is a schematic view illustration of a machine tool path for an exemplary discontinuity, having a curved, stairstep geometry, relative to boundaries of upper and lower portions of the transponder chip opening for another exemplary card embodiment. 
         FIGS. 31B-31F  are a perspective view (B) and plan view illustrations of the front surface (C), top side (D), left side (E), and back surface (F), respectively, of an exemplary card having the discontinuity depicted in  FIG. 31A . 
         FIG. 32  is a cross sectional illustration of an exemplary card embodiment showing exemplary optional layers over and under the metal layer. 
         FIG. 33  is a cross sectional illustration of an exemplary card embodiment showing a surface coating with various exemplary markings and engravings. 
         FIG. 34  is a cross sectional illustration of another exemplary card embodiment, showing a discontinuity partially filled with a surface coating. 
         FIG. 35A  is a plan view of a front surface of an exemplary card with a discontinuity and an exemplary pocket for receiving a reinforcing tab. 
         FIG. 35B  is perspective view from the front left side of the card of  FIG. 35A  prior to receiving reinforcing tabs. 
         FIG. 35C  is an exploded perspective view from the front left side lower corner of the card of  FIG. 35A , showing the placement of reinforcing tabs. 
         FIG. 35D  is a perspective view of an isolated front tab as depicted in  FIG. 35C . 
         FIG. 35E  is a perspective view of an isolated back tab as depicted in  FIG. 35C . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 1A-7  show an exemplary transaction card or portion of a card  100 , having a card periphery  101  defined by left side  104  (also depicted in  FIG. 3 ), right side  106  (also depicted in  FIG. 4 ), top side  108  (also depicted in  FIG. 5 ), and bottom side  102  (also depicted in  FIG. 6 ). Left side  104  and right side  106  are parallel to one another, and top side  108  and bottom side  102  are parallel to each other. Sides  104  and  106  may be referred to as the “relatively shorter” sides and sides  108  and  102  referred to as the “relatively longer” sides. The portion of the card illustrated in  FIG. 1C  is a metal layer  100  having a front surface  112  (also depicted in  FIG. 2 ) and a back surface  114  (also depicted in  FIG. 7 ). It should be understood that the terms “front” and “back” are used herein for differentiation of the opposite surfaces, and no particular significance is intended by the use of these terms. Similarly the terms right and left and top and bottom are used to refer to the sides that form the periphery of the card, which terms are oriented from a view of the front surface of a card as depicted in, e.g.,  FIG. 2 , but again, this terminology is for ease of description only. Similarly, the term “side” is used herein to refer to the sides that form periphery of the card, and the term “edge” is used to refer to the edges of the boundary of the opening, but the use of these terms is intended only for differentiation, without specific significance to the terminology used. 
     As depicted in  FIGS. 1B, 1C and 2 , an opening  120  in the metal layer  100  is sized to accommodate a transponder chip module  121  having a front surface  127  and a back surface  126  (as shown in  FIG. 3 ). The details of the transponder chip module are not a claimed feature of the invention and are shown for illustrative purposes only. Although an 8-pin module is shown, the transponder may have fewer or more contacts, such as for example, a 6-pin module. Those of skill in the art will recognize that any number of different transponder chip designs are available and may be used in an exemplary card. 
     As shown in more detail in  FIG. 1B , the opening has a left edge  124  parallel and relatively closest to the left short side  104  of the card periphery  101 , a second edge  128  parallel and relatively closest to the top side  108  of the card periphery, a third edge  122  parallel and relatively closest to the bottom side  102  of the card periphery. Left edge  124  is relatively closer to the left side  104  of the card periphery than the top edge  128  is to the top side  108  of the periphery, and the top edge  128  is relatively closer to the top side  108  of the periphery than the bottom edge  122  is to the bottom side  102  of the card periphery. The edges of the opening  120  define corners (e.g. a top left corner  125  formed by edge  124  and edge  128  and a bottom left corner  123  formed by edge  124  and edge  122 ). 
     A discontinuity or slit  130  in metal layer  100  comprises a gap in the metal layer extending from the front surface  112  to the back surface  114  of the metal layer  100 . The terms “discontinuity” and “slit” may be used interchangeably herein. The discontinuity defines a path from an origin (O) at the card periphery and terminating at a terminus (T) in the periphery of the opening. In the embodiment shown in  FIGS. 1A-C , the terminus is located relatively closer to corner  125  than to the adjacent corner  123  defined by common edge  124 . Most if not all of the other inventive embodiments depicted herein show the terminus located relatively closer to one corner than the other corner defined by the common edge. This is in contrast to prior art designs that depict the slit terminating in a location at a midpoint between adjacent corners  123  and  125 . 
     As depicted in  FIGS. 1A and 1B , the opening and the discontinuity reflect an intermediate step in the manufacture of the card. Opening  120 , as depicted, is a stepped pocket opening that defines an overall area having an outer boundary  144  and an inner boundary  146 . An upper portion (open to the front surface of the card) of the stepped pocket opening has an open area defined by the outer boundary  144 . A lower portion of the pocket (open to the back surface of the card) has an area defined by inner boundary  146 , wherein the area of the lower portion of the pocket is less than the area of the upper portion of the pocket. The wall between the inner boundary and the outer boundary along the direction of the thickness of the card defines a ledge  147  between the inner boundary and wall of the upper pocket and having a surface parallel to the upper and lower surfaces of the card. It should be understood that as used herein, the term “parallel” as used in connection with any and all comparative features is intended to mean parallel within a desired tolerance, but may include features that are not precisely parallel. The discontinuity is depicted as having an endpoint E located on the inner boundary  146 . 
       FIG. 1A  depicts a “tool path and milling boundary view” of the card of  FIGS. 1B and 1C .  FIG. 1A  schematically reflects discontinuity  130  as a line showing a tool path for the cutter (e.g. laser) for generating the discontinuity. Thus, the line  130  in  FIG. 1A  extends past the origin O on the periphery of the card and past the endpoint E on the inner boundary of the opening. The manufacturing boundary lines corresponding to the opening depict the locations of the inner boundary  146  and outer boundary  144  of the upper and lower pockets generated by the pocket-making process, which may be performed by milling tools, etching tools, lasers, and the like. Sequentially, during manufacture of the card, the discontinuity may first be cut in the metal layer, such as with a laser, along a line including origin O and endpoint E and which may extend past both origin O and endpoint E to ensure a complete cut through the metal layer. Then the upper and lower pockets are milled. Thus, although depicted in the tool path view of  FIG. 1A  with the endpoint of the discontinuity located inside the inner boundary  146 , in a completed metal layer, such as is shown in  FIG. 1B , the discontinuity actually ends at the inner boundary  146  at point E, but from the front of the card as depicted in  FIG. 1C , the discontinuity is only visible to the edge of the outer boundary  144  at point T, because of the payment module inserted in the opening. Because only the inner boundary  146  extends through the back surface  114  of the metal layer, the discontinuity  130  extends to the endpoint E on the back of the card. It should be understood that the design of the transponder chip depicted herein only illustrates an exemplary contact pattern, and the invention is not limited to any particular pattern. It should also be understood that although the discontinuity  130 , the inner boundary  146 , and the back surface of the module  126  are depicted on the back of the metal layer in  FIG. 7 , layers over the back surface of the card may fully or partially obscure visibility of the discontinuity, the transponder chip, and the opening, depending upon the nature and opacity of the back layer. In general, the opening and transponder chip are typically obscured from view by an opaque member or portion of a layer, but some portion of the discontinuity may be detectible from the back side, if viewed closely and if an optional back layer of the card is not fully opaque. It should further be understood that the contacts on the top surface  127  of the transponder module are preferably flush with the outermost front surface of the card. If the metal layer is the top layer, the contacts will be flush with the front surface of the metal layer. If another layer, such as a clear plastic layer or a ceramic layer, are disposed on top of the metal layer, however, such as depicted in  FIG. 32 , the contacts will be mounted flush with the top layer  1200 . 
     After creating the discontinuity, the opening may be cut by first milling the lower portion and then milling the upper portion, or vice versa. The lower portion may be milled from the back surface of the card, and the upper portion from the front surface of the card (although both portions may be milled from the front surface). In some embodiments, a non-conductive material may be provided in the opening by any of the methods described in U.S. Pat. No. 9,390,366, incorporated herein by reference. When the payment module is eventually mounted in the opening, an upper portion of the module rests on ledge  147  and the integrated circuit on the back of the module is disposed in the lower portion. The geometry of the lower portion of the pocket (e.g. defined by boundary  146  in  FIGS. 1A and 1B ), specifically its length (X dimension—parallel to the long sides  102 ,  108  of the metal layer) and width (Y dimension—parallel to the short sides  104 ,  106  of the metal layer) in the plane coextensive with the back surface of the card, has an impact on RF performance. For example, acceptable ranges of performance for a 6-pin payment module may have X and Y dimensions preferably in a range of 3-10 mm, more preferably X=7.9 mm to 8.9 mm and Y=4.5 mm to 6.0 mm, and most preferably 7.9 mm×5.3 mm. For an 8-pin payment module, acceptable ranges of performance may have X and Y dimensions preferably in the range of 7 mm to 10 mm, and more preferably in the range of 7.5 mm to 9.5 mm. The size of the gap in the discontinuity may also impact performance, with the gap size preferably less than 1 mm, more preferably less than 0.5 mm, and most preferably about 0.1 mm, plus or minus 0.05 mm. The invention is not limited to any particular discontinuity gap size or dimensions of the lower portion of the pocket, however. In the embodiment depicted in  FIGS. 1A-2 , the left side  104  of the card has a region  150  (shown in  FIG. 2  only, to reduce clutter) that is aligned with (e.g. coextensive with and parallel to) the left edge  124  of the opening  120 /transponder module  121 , and the origin (O) for the discontinuity is located on card periphery  101  outside region  150 . In the embodiment depicted in  FIG. 1 , the terminus is located at corner  125 . 
     Depicted in  FIGS. 8A-31A  are various other slit configurations, each of which can be characterized in numerous ways and may have certain features. Each  FIG. 8A ,  9 A, etc. depicts the manufacturing path or boundary lines associated with each slit design. For the illustrations of the manufacturing path lines, the line  802 ,  902 , etc. corresponding to the slit as depicted corresponds to the tool path for the cutter (e.g. laser) for generating the discontinuity. The manufacturing boundary lines corresponding for the opening depicts the inner (e.g.  804 ,  904 ) and outer (e.g.  806 ,  906 ) boundaries of the upper and lower pockets generated by the pocket-making tools, which may be milling tools, etching tools, lasers, and the link. The finished metal layers of the cards, in each case, however, conform to the designs as shown in  FIGS. 8B-8F, 9B-9F , etc., in which, for example,  FIGS. 8B, 9B , etc. depict the front view perspective views of the metal layer of the respective cards,  FIGS. 8C, 9C , etc. depict front surface views,  FIGS. 8D, 9D , etc. depict top (or bottom) side views,  FIGS. 8E, 9E , etc. depict left side views, and  FIGS. 8F, 9F , etc. depict back surface views. As should be understood, the one of the top side view or bottom side view depicted is selected to show the side of the card on which the origin (O) of each discontinuity is located, whereas the one of the top or bottom side view not depicted is essentially identical to  FIG. 6 . Likewise, the right side view for all of the aforementioned embodiments is essentially identical to the side view depicted in  FIG. 4 . 
     It should also be understood that  FIGS. 8A-F  to  31 A-F depict only the metal layer of the exemplary cards. The metal layer may have one or more layers disposed over the front surface or the back surface of the card, and each additional layer may cover the entire surface or only a portion of the surface. The metal layer itself may comprise a composite of multiple metal layers, including embodiments in which at least one layer comprises a different metal than another. The additional layers may comprise, for example, any of the layers described in U.S. Published Pat. App. No. US20150339564A1 and/or US20170316300A1, incorporated herein by reference in their entireties. A preferred embodiment may comprise a ceramic coating on the front surface of the metal card and a plastic layer on the back surface of the card. 
     Referring now to the slit configuration depicted in  FIG. 8A , the origin (O) is located relatively closer to the line defined by the top side  108  than the terminus (T). This characterization is also true of the slit configuration depicted in  FIG. 1 , in which the origin (O) is located on the top side  108 . The location of the origin relatively closer to the line defined by the top side of the periphery than the terminus is also true of at least the designs depicted in  FIGS. 9A, 10A, 12A, 14A-17A, 19A-21A, 30A , and  31 A. In other designs, the location of the terminus is located relatively closer to the line defined by the top side  108 , such as in the slit designs depicted in  FIGS. 22A-24A . The term “line defined by the top side” refers to the imaginary line in space along which the top side  108  lies. Because the cards have rounded corners, the distance from the origin to the line defined by top side  108  is measured from intersection of the line defined by the top side  108  and the line defined by the left side  104 , which point is not actually physically present as part of a metal layer having standard rounded corners. Thus in each of the foregoing exemplary embodiments, one of the terminus or the origin are located relatively closer to one long side of the periphery than the other. In other embodiments (e.g.  FIGS. 11A, 18A , others) the terminus and the origin may be located approximately the same distance from the top or bottom sides. 
     It should be understood that although the term “origin” and “terminus,” although representative of one method of constructing the discontinuity in which the cut line begins at or before the origin and extends in the direction of and beyond the terminus as further described herein, the use of these terms does not imply a specific manufacturing method or direction of the cut for forming the discontinuity. Furthermore, although referred to as a “terminus,” as explained elsewhere herein, the terminus is only the location where the discontinuity meets the opening on the top surface of the card, and the discontinuity actually extends further inward to the periphery of the opening in the back surface of the card. Finally, although the front, upper left of the card is traditionally the location for the contacts, relative to what a consumer considers the “front” of a finished card containing the card branding, card number, and the like, it should be understood that in other embodiments, the contacts may be located in a mirror image position on the lower back right of the card and provide equivalent functionality, with the discontinuity similarly located relative to the back surface of the card as depicted herein relative to the front surface. Thus, the “front” and “back” surfaces of the card, as used herein, are relative to the disposition of the transponder module and do not necessarily reflect a traditional “front” or “back” as those terms might be used by a consumer in receipt of the final card. Of course, the location of the contacts is dictated by the arrangement of card readers that read the cards via a physical connection, and it should be understood that the location of the transponder chip relative to the periphery of the card is not limited by the invention. 
     In certain embodiments, the discontinuity path comprises at least two changes in direction of 90 degrees or more. For example,  FIGS. 9A, 19A, and 31A  illustrate stairstep designs in which the discontinuity path makes multiple 90 degree changes in direction. In the embodiments depicted in  FIGS. 9A, 19A, and 31A , the stairstep geometry has a rise (vertical distance covered between adjacent horizontal sections) and a run (horizontal distance covered between adjacent vertical sections), in which the rise is greater than the run. In other embodiments, not shown, the rise and run may be equal or the run may be greater than the rise. In the embodiments depicted, the rise and run are roughly equal for each step, but in other embodiments, the rise and run may be different in at least one step relative to others in the series of steps. 
       FIGS. 11A and 13A  illustrate sawtooth geometries in which the path of the discontinuity makes multiple changes in direction of more than 90 degrees.  FIG. 12A  illustrates a discontinuity path that has a micro stairstep geometry and a macro sawtooth geometry, comprising at least a first plurality of more than two changes in direction of 90 degrees leading to a first change in direction of more than 90 degrees and a second plurality of more than two changes in direction of 90 degrees leading to a second change in direction of more than 90 degrees. Again, although depicted with each “tooth” in the sawtooth geometry of roughly equal dimension, the invention is not limited to such geometries. 
     The discontinuity path may also have at least one section of curved geometry. A basic curved geometry is illustrated in  FIG. 10A , but the curved design may also have one or more changes in direction greater than or equal to 90 degrees, wherein at least one of the changes in direction has a curved geometry. The embodiments illustrated in  FIGS. 14A-18A  depict such features, with the discontinuity paths illustrated in  FIG. 14A-16A  each having a sinusoidal shape for at least a portion of the path comprising at least two changes in direction of more than 90 degrees. 
     Although the paths shown in  FIGS. 14-16  are generally sinusoidal in nature, a curved path with multiple changes in direction may also have portions that complete a change in direction of more than 180 degrees before making a subsequent change in direction of more than 180 degrees, as depicted in  FIGS. 17A-C . Also depicted in  FIGS. 17A-C , the size of each section encompassing a 180 degree change in direction may vary over the length of the path from a relatively smaller section  1712  to a relatively larger section  1714 . 
     The path in  FIG. 31A  depicts sections of curved geometry within a stairstep architecture, comprising a radius or fillet instead of a right angle for each change of direction of 90 degrees. Such a path may enable faster operation of the cutting tool and/or may be aesthetically more pleasing than the embodiment with sharp direction changes. 
     In some embodiments, such as depicted in  FIGS. 15A-18A , the terminus of the discontinuity may be located on the top edge opening with the origin located on the left side of the card. In other embodiments, such as depicted in  FIGS. 1A-7 , and  FIG. 22A-F , the discontinuity may be located on the top or bottom side of the card periphery and the terminus may be on the top or bottom edge or a top or bottom corner of the opening. 
     In some embodiments, such as depicted in  FIGS. 9A, 19A, and 30A , the discontinuity has a terminus located on the left edge of the opening at a location relatively closer to the bottom left corner  125  than the upper left corner  123  and has an origin in the left side of the card periphery in a location relatively closer to the upper left corner  123  than the bottom left corner  125 . In other embodiments, such as depicted in  FIGS. 8A, 10A, 15A, 20A, and 21A , the terminus location is relatively closer to upper left corner  123  than the bottom left corner  125  and the origin is located in the left side of the card periphery relatively closer to the upper left corner  123  than the bottom left corner  125 . In other words, the paths of the discontinuities for both of the foregoing types of embodiments are generally diagonal and downward from the origin to the terminus, but the first group terminates on the left edge of the opening closer to the bottom corner than the top corner. 
     As described above and depicted in the figures, e.g.,  1 C,  8 C,  9 C, etc., in a completed metal layer of the card, a transponder chip module  121  is disposed in the opening, and the metal layer serves as an amplifying antenna for the transponder chip module. In final card embodiments incorporating any of the metal layers depicted and described herein, such as layer  1100  depicted in  FIG. 32 , the card may comprise at least one non-metal layer  1200 ,  1300  disposed on at least one surface of the metal layer  1100 , such as but not limited to a plastic layer, a ceramic layer, a decorative layer comprising one of wood or leather, or a combination thereof. Different types of layers, or combinations thereof, may be disposed on different surfaces of the card. As used herein, the term “disposed” does not denote a direct connection to the respective surface, but also an indirect connection (i.e. on top of one or more other layers that are directly connected to the surface). 
     In one preferred embodiment, wherein metal layer  1100  has a stairstep shaped discontinuity  902 ,  1902 ,  3102 , such as is depicted in, for example,  FIGS. 9A-C ,  19 A-C and  31 A-C, the card may have a front surface coated with ceramic layer  1200  and a back surface on which a plastic layer  1300  is attached, preferably by an adhesive. As is known to one of skill in the art, attachment of a plastic layer with an adhesive may comprise employing a carrier substrate (e.g. polyester) having adhesive (e.g. an ethylene copolymer adhesive, such as ethylene acrylic acid (EEA)) on both sides. As depicted in the cross sectional diagram of  FIG. 34 , in embodiments with a ceramic layer  3400  comprising a ceramic coating over the metal layer  3410 , the gap  3402  defined by the discontinuity may at least partially filled with the ceramic coating, leaving a surface imperfection  3404  still visible from the top surface of the ceramic coating. 
     The discontinuity as described herein may be optically visible from one or both surfaces of the card. In some embodiments, such as one in which the back surface is covered with an opaque plastic or translucent plastic with opaque ink, the discontinuity may not be visible from the back surface. In embodiments with front decorative layers, such as wood, leather, or certain ceramics, the discontinuity may also be hidden from the front. In some ceramic-coated embodiments, however, the ceramic coating may only partially fill the gap caused by the discontinuity, thereby making the discontinuity still visibly perceptible, at least as a surface imperfection  3404  as depicted in  FIG. 34 , which imperfection may be in the form of at least a perceptible line, if not a perceptible gap. Thus, it should be understood that in the drawings depicting a finished metal layer, that metal layer may be a top layer, or it may be a layer that is covered with another layer but still visibly perceptible in some way. 
     In still other discontinuity embodiments, the card may comprise a plurality of discontinuities, such as in the embodiments depicted in  FIGS. 25A-28A . In all of the embodiments depicted, at least one of the plurality of discontinuities (e.g.  2502 ,  2602 ,  2702 ,  2802 ) has a length equal to a shortest length from the opening to the periphery of the card, and at least two of the plurality of discontinuities (e.g.  2502  and  2504 ,  2602  and  2604 , etc.) are parallel to one another. In some embodiments, such as depicted in  FIG. 25A , fewer than all of the plurality of discontinuities may extend from the periphery to the opening, meaning that one or more discontinuities (e.g.  2506 ) may extend from only the periphery of the card or the periphery of the opening, but not to both and/or one or more discontinuities (e.g.  2508 ,  2509 ,  2510 ) may not extend to either the periphery of the card or the periphery of the opening. In multiple-discontinuity embodiments, the presence of multiple discontinuities spreads the stress associated with flexure across multiple locations, minimizing the stress whitening attributable to any one discontinuity. In the embodiments depicted with multiple slits extending from the card periphery to the opening, metal areas disposed between such slits are held in place by the overlying and underlying non-metal layers of the card. 
     In a method for making a transaction card as described herein, the method comprising the steps of (a) providing a metal layer having an front surface and a back surface; (b) creating an opening in the metal layer sized to accommodate a transponder chip module, having the features described herein, (c) creating a discontinuity in the metal layer as described herein, and (d) disposing the transponder chip module in the opening. As described above, the step of creating the discontinuity may precede the step of creating the opening for the transponder chip module. 
     As described above, the method may comprise at least partially filling the gap defined by the discontinuity with a non-metal material, such as ceramic. The method may also further comprise disposing at least one non-metal layer on the front surface or the back surface of the metal layer, such as by adhesively bonding the non-metal layer to the metal layer, or by spray coating a ceramic layer onto the metal layer. In some embodiments, the non-metal layer comprises a ceramic layer having a color, in which the method further comprises using a laser to create one or more permanent markings on the ceramic layer having a different color than the ceramic layer color, as described in more detail with respect to  FIG. 33  later herein. In some embodiments, the permanent markings in the ceramic may arise from a chemical change of a pigment within the ceramic composition, or the permanent markings may arise from removing an overlying ceramic layer to reveal an underlying layer having a different color. The underlying layer with the different color may comprise an underlying ceramic layer, if multiple layers of ceramic are provided. For example, it has been found that for certain types of cured ceramic spray coatings comprised of ceramic microparticles containing, e.g., zirconia dioxide, aluminum disilicide, pigment, and a curable resin binder suspended in a carrier solution, a white colored base ceramic layer having a white pigment therein may have better adhesion than a layer having a colored pigment, and therefore a first, white layer may be disposed underneath a second, non-white layer of ceramic. Or, multiple ceramic layers may be used for aesthetic purposes. In other embodiments, the exposed underlying layer having the different color may be the metal layer. In still other embodiments, a composite metal core may facilitate the appearance of different colors depending upon the depth of the engravings. The engraving may be performed by any method, such as a chemical or mechanical method, and is not limited to laser marking. Finally, grooves in the ceramic may be filled with another substance, such as metal. For example, a ceramic-coated steel card may have laser engraved grooves in the ceramic coating that penetrate to the metal, and then a noble or precious metal, such as gold, silver, platinum, or the like, may be electroplated into the groove as a filler. 
     The various configurations comprising the ceramic layers as described herein are not limited to card embodiments having a discontinuity in the metal layer as described herein. Although the ceramic layer may comprise one or more layers of a ceramic coating applied directly to the metal and cured, other methods of providing the ceramic layer may include adhering a freestanding monolithic ceramic layer to the metal layer or disposing a ceramic coating on a substrate, and then adhering the ceramic-coated substrate to the metal layer. In another method, a ceramic layer may be created by tapecasting and adhered to the body. 
     Cards with slit geometries as shown and claimed herein have functional advantages over cards with straight slit geometries or other geometries of the prior art, per the examples noted herein. While all of the discontinuity designs may have functional advantages over prior art designs, some more than others, and all or most may have relatively similar production costs, some may be considered more aesthetically pleasing than others and thus may be favored purely for aesthetic reasons. Thus, certain features of the discontinuities in the metal layers disclosed herein may be selected for ornamental design and are not dictated by practical function. Accordingly, design elements of each may be varied and selected while maintaining functionality, such that a variety of ornamental configurations are available with substantially the same function or performance. As non-limiting examples, the exact contours of the discontinuity, such as the number of steps or zig zags, rise or run of steps, curved or non-curved changes in direction, degree of curvature or changes in direction, precise locations of the origin, terminus, and any inflection points, and the number of discontinuities in embodiments with a plurality of discontinuity, may be varied to provide different ornamental appearances while maintaining substantially the same functionality. The ornamental design of the metal layer may be protected separately in one or more U.S. design patent applications. 
     The use of alternative slit designs enable a traditional metal or ceramic-coated metal card to overcome potential weaknesses at the slit, which allow the card to maintain the traditional metal feel and sound. Another option for reinforcing the card is to use a self-supporting layer on the back of the card, such as an FR4 material (a thermoset laminate made with epoxy resin and woven fiberglass) or polyimide. Printed layers, such as for the various indicia, magnetic stripe, etc., may be assembled with the FR4 layer or printed directly on the FR4 layer. For example, in one embodiment depicted generally in  FIG. 32 , a relatively thin (e.g. 0.009 inches thick) stainless steel substrate  1100  may be used with an FR4 backing layer  1300 . In another embodiment, an 18 mil stainless steel layer may have on its back side a 4 mil FR4 layer (attached to the steel layer with a 2 mil adhesive layer), a 5 mil printed sheet on the back of the FR4 layer (attached via another 2 mil adhesive layer), and a 2 mil overlay layer comprising the magnetic stripe laminated to the back side of the print sheet layer. The print sheet and mag stripe overlay layers are the layers vulnerable to stress whitening, which the reinforcing layer helps to prevent. While reinforced backing may enable the weakness of the slit to be overcome sufficiently without a need to use one of the other slit designs described herein, embodiments combining both an FR4 (or other self-supporting) layer and one of the slit geometries depicted herein may also be provided. Preferable self-supporting layers have a rigidity of 80 MPa·m 3  to 40 GPa·m 3 . 
     Thus, referring now to  FIG. 32 , there is shown a cross-sectional illustration of an exemplary card embodiment  1000 , showing the metal layer  1100 , which may be any metal layer as described herein, with or without a slit, and having a stepped opening  1005  therein, including an opening upper portion  1010 , the opening lower portion  1012 . Also illustrated in  FIG. 32  are a front layer  1200  and a back layer  1300 . Layer  1200  has an opening  1205  that matches (i.e. is coextensive with) opening upper portion  1010 , so that the contacts of a transponder module disposed in the opening in the metal card will sit relatively flush with the upper surface of layer  1200 . The thicknesses of the layers depicted in any of the drawings herein are not to scale. In some embodiments, the front layer as depicted in  FIG. 32  may represent a plurality of layers, the back layer as depicted may represent a plurality of layers, the metal layer as depicted may represent a plurality of layers, or any combination thereof. Layers  1200  and  1300  are both optional. In one embodiment, layer  1200  may comprise a 9 mil PVC or PVC/PEEK composite layer on the front of a 10 mil metal layer and a 10 mil PVC layer on the back of the metal layer. The front and back layers may each be adhered to the metal layer with 2 mil adhesive layers, such as a polyester substrate having EEA adhesive on both sides, as is well known in the art. Some embodiments may have only a front layer or a back layer, but not both, and some metal card products may have no additional layers other than a coating to promote printability on the metal. For example, the card may comprise a printable metal such as printable stainless steel having a coating at least on its front face that improves acceptance of printing inks on the stainless steel surface. The coating may comprise, for example, a polyester based coating receptive to UV curable screen and inkjet inks or solvent or oxidation printing. 
     It should be understood that one manufacturer may provide the metal layer as an intermediate to a finisher that may add additional layers as part of later processing. In one embodiment, as described herein, front layer  1200  comprises a ceramic layer (applied to the metal layer by any of the methods described herein) and back layer comprises a plastic layer. In another embodiment described herein, back layer  1200  may be a self-supporting layer, such as a layer made from FR4. 
     As illustrated in  FIG. 33 , in some embodiments, a ceramic layer  3300  on a metal layer  3302  may comprise at least two ceramic layers  3312  and  3314 , each layer having a different color. Similarly, metal layer  3302  may comprise at least two metal layers  3322 ,  3324 , and the two metal layers may be different metals having different colors. Creating a design in the ceramic layer may comprise making laser markings  3330  that change a color in the ceramic layer by permanently chemically changing a pigment in the ceramic layer, or by removing a portion of the ceramic to make a groove. Such a groove may be a superficial groove, such as groove  3331  that does not penetrate the upper layer to reveal underlying layers, or may be a groove that reveals an underlying layers. Grooves may be created with laser, mechanical, or chemical methods known in the art. Grooves that reveal an underlying layer may include grooves  3332  that remove one ceramic layer  3312  to reveal another ceramic layer  3314 , grooves  3334  that remove all ceramic layers  3312  and  3314  to reveal an upper metal layer  3322 , and grooves  3336  that remove all the ceramic layers  3312 ,  3314  and the upper metal layer  3322  to expose an underlying metal layer  3324 . Still another design technique may include creating a groove (such as any of the groove embodiments described above) and then filling that groove in the ceramic with another material, such as an electroplated metal  3338 , which may be a different metal than one or both of the other metal layer or layers. For filling a groove by electroplating, the initial groove is preferably a groove  3334  or  3336  that removes the ceramic down to a metal layer. Although presented in a single embodiment for illustrative purposes only, each of the various grooves and marking techniques may be practiced alone or in any combination with others described herein. And although described in combination with the various embodiments disclosed herein for reinforcing a slit card design, the various techniques for creating decorations in a ceramic card are not limited to such embodiments. 
     Yet another embodiment of strengthening a section of a card having a discontinuity comprises providing a supporting tab overlying and/or underlying the discontinuity, such as for card  3500  depicted in  FIGS. 35A-E . In an exemplary embodiment, such as for a “full metal” card, having no co-extensive layers on the top or back surface of the card (except, optionally, a coating to promote printing), pockets  3510 ,  3512  around the opening  3520  for the module (not shown) are recessed in the axis on both sides of the card. Pockets  3510 ,  3512  on opposite sides of the card, both of which of which have an area that is less than the area of the metal layer, are depicted as the same size as one another in the figures, but can be different sizes. Non-metal inserts  3540 ,  3550 , such as ceramic or plastic, are placed into the pockets  3510 ,  3512 . In a similar design for a “hybrid/veneer card” (having one or more non-metal layers on the back side of the metal layer, typically coextensive with the metal layer), a pocket and corresponding insert may be provided only in the front. Front insert  3540  has a hole  3545  to accommodate the module and expose the contact portion of the module on the top surface of the card. The use of an insert construction, such as is disclosed herein, may avoid the need to provide a stepped pocket for the transponder module in the metal layer, as the thicknesses of the pockets on either side may be selected so that the “lip” (larger periphery portion) of the module (not shown) rests on the shelf created by the card body and the portion on the back of the module protrudes through the hole  3520  in card body and stops short of the inner surface of the rear insert  3550 . Artwork may be applied to the inserts by laser or any means known in the art. 
     It should be understood that any of the methods disclosed herein for strengthening an area around a discontinuity of a card (specific single slit geometries, multiple-slit geometries, reinforcing layer(s), or reinforcing pocket insert) may be practiced alone or in combination with one another. 
     Any other methods of creating designs or providing indicia on card as are well known in the art may also be provided, including providing a signature block, a magnetic stripe, a hologram, branding indicia, personalization information, and the like. 
     EXAMPLES 
     Exemplary slit design embodiments as depicted herein showed less ink cracking substrate stress whitening after short dimension bending (bending parallel to the long edges) than other cards, when subjected to a Dynamic Bending Stress Test (ref ISO/IEC 10373-1:2006). Various embodiments were tested up to 500 Flex Test Cycles at a rate of 30 cycles/minute per axis. 
     
       
         
           
               
               
               
             
               
                   
                   
               
               
                   
                   
                 Bend 
               
               
                   
                   
                 Cycles Across 
               
               
                   
                 Design 
                 Short Axis 
               
               
                   
                 (by reference 
                 Before Stress 
               
               
                   
                 to FIG. # 
                 Whitening 
               
               
                   
                 where depicted) 
                 Induced 
               
               
                   
                   
               
             
            
               
                   
                 Linear near 
                 Immediate 
               
               
                   
                 center of 
                   
               
               
                   
                 chip cavity 
                   
               
               
                   
                 FIG. 29 
                  &lt;50 
               
               
                   
                 FIG. 1  
                  &gt;50 
               
               
                   
                 FIG. 23 
                 &gt;250 
               
               
                   
                 FIG. 19 
                 &gt;250 
               
               
                   
                 FIG. 9  
                 &gt;500 
               
               
                   
                 FIG. 15 
                 &gt;500 
               
               
                   
                   
               
            
           
         
       
     
     Although the invention is illustrated and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims and without departing from the invention. 
     Furthermore, although the discontinuity geometries shown herein have functional advantages over prior art geometries, it should be understood that there are potentially an infinite variety of geometries available, and that those depicted herein are merely a small subset of the myriad geometries available that conform to the claims. Among the myriad geometries available, including the myriad variations of a particular geometry, which may exhibit suitable performance and function, there may be certain designs that are preferred for purely aesthetic reasons. Accordingly, inclusion of any specific design herein representative of a particular geometry is not an indication that the specific design is functionally better than an alternative design of a similar or even a different geometry, except as specifically noted. Similarly, to the extent a pattern with multiple changes of direction may have certain advantages, the number of directional changes after a threshold number may be selected primarily for aesthetic reasons. Accordingly, the description herein is provided without prejudice to any number of design patent applications relating to the specific designs presented herein. Features shown in solid lines in the utility patent drawings herein are without prejudice to showing the same in dashed lines to signify their non-inclusion within the scope of the design patent claims. In particular, one or more features visible on the back surfaces of the metal layer embodiments depicted herein may or may not be visible in a completed card, because of one or more overlying layers and thus may be depicted in dashed lines when depicting claimed design attributes, to show that such features are not claimed. Similarly, the details of the transponder module contacts are not a claimed aspect of the invention, and may be depicted in dashed lines in any drawing depicting claimed design attributes. 
     Although certain embodiments with multiple changes of direction have been depicted, it should be understood that embodiments with fewer or more changes of direction are also possible. Similarly, while certain embodiments depict locations of the origin O and terminus T in specific locations for a particular style of discontinuity, it should be understood that the locations of each may be varied along the periphery of the card or the periphery of the opening in the card.