BPG Atlases, Foldouts, and Guarded Structures

Book and Paper Group Wiki > Book Conservation Wiki > Atlases, Foldouts, and Guarded Structures
This page discusses the varieties of foldouts, guards, attachment methods, and compensation that we encounter in books, how they affect the function of the book, and how we can best treat books with these elements. This page focuses on atlases (bound collections of maps), but foldouts and guards appear in many genres.
This page is related to the pages on Sewing and Leaf Attachment and Leaf Attachment and Sewing Repair.
Wiki Compiler: Katherine Kelly
Wiki Contributors: Karissa Muratore, Abigail Slawik, your name could be here
==Structures and Preservation Challenges==
===Folds and Fold Position===
A simple bifolio map whose fold runs parallel to the spine of the book can be attached at the center fold or on one end. Center attachment allows the vulnerable fold to be protected within the binding. However, it must be placed far enough away from the gutter to allow the map to open flat. Center attachment is very intuitive, as a reader turning pages naturally comes to the page. Side attachment is less intuitive, and a careless reader may tear the fold in an attempt to open the page. Folds located at the book edges are also subject to environmental damage as the fold is exposed to air, moisture, and pollutants (Spitzmueller 1996). Once unfolded, side attached maps can face the text of the book.
For a two-panel map whose fold runs perpendicular to the spine of the book, it is easier to fold a panel up and away from the reader, particularly with very large books. This top-up configuration is also easier to display in a traditional book cradle. However, the bottom down method appears to have been favored by binders as it left a clean edge at the head which could be trimmed and decorated.
For maps with multiple folds running parallel to the spine of the book, there are a few folding patterns to avoid. The squashed scroll is time consuming to refold, and has many nested folds that can confuse the reader. Irregular folding patterns can also confuse the reader, leading to misfolded maps. An accordion fold, on the other hand, is regular and intuitive. Having the text face upwards and the free end positioned near the fore edge also provides a visual cue to the reader about how to unfold the map.
Folds are slightly thicker than a double thickness of paper would be, and if many folds are stacked on top of one another or around each other, they add bulk. This can be reduced with staggered folds.
 
Cross folds occur when vertical and horizontal folds intersect. As they cross, one of the folds remains in one orientation – mountain or valley – and the other switches. When the map flexes, the mountain and valley folds are in conflict. This leads to tears that begin at the center point and propagate outwards.
Cross folds can also lead to compression creases because the outer section must stretch around the inner, despite them being the same size. Paper can be squeezed and stretched up to a point. This allows cross folds to happen, but results in weakened outer folds and crimped inner folds.
===Types of Guards===
There are three main types of guards used for attachment of pages. The first is a reversed v-guard or meeting guard, where gatherings are sewn through their center folds onto guards (Conroy 1987; Minter 2015). 
The other two types of guards are adhesive. The image on the left shows guards of uniform thickness. A moderately stiff paper extends from the plate to the gutter where it is folded over and sewn along with the rest of the book.
The image on the right is a laminate guard construction. Multiple layers provide stiffness in the gutter, and a single layer flexes across a small gap. The flexible gap allows the plates to open flat without requiring the plate to flex.
The materials used for these types of guards are discussed more in the section below on Guarding
===Attachment===
 
Plates or foldouts can be non-adhesively attached by sewing them along with the rest of the book through an extended edge. This is referred to as guarded in or sewn in. More commonly, the plate or foldout is tipped to a guard or a leaf with a line of adhesive. That strip of map-adhesive-guard forms a thick sandwich. This can be unusually weak, if poor quality adhesive has caused chemical damage to the paper, or it can be excessively stiff and strong, leading to a breaking edge just to the side of the sandwich.
If a foldout taller than the book is sewn or adhered right up to the spine edge, it must be lipped, meaning that a part is cut away to allow it to fold into the book without catching in the gutter. This internal corner is vulnerable to damage and frequently tears as the map is handled.
===Compensation===
When a thick foldout is attached into a binding, it can make the book too thick at the fore edge. Compensation is the general term for material added in the gutter of a bound volume to compensate for the thickness of bulky material positioned towards the fore edge. Many bookbinding manuals discuss compensation, and a wide variety of materials and methods are suggested. Paper is most common, but cloth and board have also been used.
The image to the left shows an even stack of paper used as compensation. These strips were probably folded at the spine and oversewn along with the rest of the book. Joseph Zaehnsdorf’s 1880 Art of Bookbinding suggests that compensation should be formed of paper strips, folded to be ¼” to 1” wide and sewn thorough the fold along with the rest of the text block (Zaehnsdorf 1880, 10). John Pleger’s 1915 Bookbinding and Its Auxiliary Branches describes using strips of paper glued together and then whip stitched as the common method, and then recommends using perforated sheets as a newer method (Pleger 1915, 41-43):
::“A common method on side-stitched pamphlets containing a number of large maps is to trim the text after gathering, and to supply the thickness of the maps with stubs one-half to three-fourths of an inch wide on the binding end. The maps and stubs are put in place and the book stitched. This besides being very slow, is hardly in keeping with the progress of the times. There are obsolete signatures in all binderies which can be utilized to good advantage as fillers by perforating them one-half to three-fourths of an inch from the fold and gathering in sufficient number to take up the thickness of the folded map. The books can be sewn on a sewing machine or stitched, and the necessity for fillers to trim and forward is obviously eliminated. After the books are bound, the places provided for the maps are cleared at the perforation, leaving the regulation stub to take up the thickness. The maps are tipped on the stubs at the left end.
Both of these techniques can leave a thick shelf of compensation against which neighboring pages can break. The image on the right shows compensation stubs that are staggered or offset from each other. They do not offer the same even appearance but are more gentle on the foldout and neighboring pages.
===The Action of the Book Spine===
All of the guarding, attachment, and compensation methods discussed above have an effect on the action of the book spine. In his 1987 article, “The Movement of the Book Spine”, Tom Conroy analyzes the codex as a moving system and talks about how the spine structure directly affects the function of the book. Conroy discusses reverse v-guards or meeting guards, where gatherings are sewn through their center folds onto guards that position them out from the gutter. The length of the guards and the pliability of the spine must be balanced - a pliable spine allows the guards to fan out and raises the opening above the level of the neighboring pages. Sufficiently long guards allow the pages to open flat, but still supported by their neighbors. In Conroy’s example, the drape of the paper is not very important because the gathering hinges at the point where the gathering is sewn to the guard. The goal is to allow the book to open flat, even if the pages are very stiff (Conroy 1987).
Guarded structures can be designed for a variety of purposes. When the goal is a foldout that opens flat, Conroy’s analysis works: the ideal configuration places the map far enough out from the gutter to escape the curve of the spine. In these cases, the book is said to have sufficient throw-up. Heavily rounded books, books with inflexible spines, and thicker books all need longer guards. This is particularly important when the map has a fold perpendicular to the spine of the book, as a flat plane of opening is necessary to avoid damage. 
Conroy does not discuss structures where the plate is attached to the guard with adhesive. In these situations, the hinging does not happen along a line of action, but is rather flexing across an area. This can either be a guard that curves up out of the gutter and is attached to a plate, or it can be a stiff laminate guard, followed by a flexible hinge which is then adhered to the plate. The adhesive attachment of plate to guard usually causes a change in flexibility, from that of the guard, to the glued sandwich, to the plate alone. This affects the drape of individual pages and the flow of the book spine as the pages are turned (Albro et al. 2012).
The image on the left shows a book that does not open well – the spine has no pliability and the guards are too short. This forces the map to flex, which has caused the stiff paper to break as it attempts to curve out from the gutter.
Guarded structures are also frequently irregular in construction, and this often causes problems with the movement of the spine. Text pages can break against the edge of a stiff stub. Unevenly thick gatherings and stiff blocks of compensation lead to preferential openings.
==Historical Techniques and Materials==
Conservators frequently find themselves undoing or working around the edges of previous treatments, and it is helpful to understand how those treatments were performed. Summarized below are a variety of historical techniques for treating and rebinding maps and guarded structures.
===Rebinding, Rearrangement, and Substitution===
Atlases, more than many other genres of printed works, were freely and frequently rearranged and updated. For many early atlases, this process began before the work even left the printer’s workshop. Atlas production methods in 17th century Amsterdam have been described as a “bibliographer's nightmare”: updated letterpress text was printed on the back of copperplate maps of many different states and dates, and “almost every atlas that left the printer’s and binder’s workshop is different from the next one in the same edition” (van der Krogt 1996, 154).
A 19th century publisher of atlases in Philadelphia advertised that his updated maps would be colored in a similar style so that substitutions could be made by the owner (Ristow 1985, 197-198). Substitutions can occur at many stages in the life of an atlas - an analysis of a 1513 Ptolemy revealed that one of the maps had been replaced with one from a newer edition shortly after printing, while another had been swapped out by a book restorer in the early 20th century (Albro et al. 2012).
Map dealers, collectors, and librarians frequently considered atlases to be mere collections of maps, to be broken up or rearranged to suit financial or organizational goals (Akerman 1991, 3-10). In addition to the map arrangement, the underlying structures of guards and prosaic bindings were rarely valued, and rebinding was common. Commercial rebinding in the 20th century frequently meant cutting off folds and oversewing, a particularly poor choice for books that need to open well.
As a general statement, one should not assume that a printed atlas is a consistent, well-understood bibliographic entity. Binding, structure, and pages should be carefully examined for inconsistencies, and a conservator should use particular caution when spot testing in preparation for humidification, mending, or washing.
===Sectioning, Lining, Lamination===
Cloth lining of maps dates back at least to the 1660s (Bagrow 1975, 16). By the 19th century, maps were frequently lined with cloth (or mounted) as part of their initial binding, and this was a standard restoration technique in the 19th and 20th centuries. Larger maps with multiple folds were commonly sectioned by cutting them along fold lines, followed by cloth lining. A gap was left between the sections to allow the map to fold. Zaehnsdorf, in his 1880 manual, calls for the linen gap to be the exact thickness of the paper. In his second edition, that is corrected to be “more than equal to the thickness of the paper” (Zaehnsdorf 1880 and 1890).
A frequently cited 1950 guide to map preservation states that, “Ideally, every map worth preserving should be mounted.” The guide provides instructions for mounting and notes that linen is preferred for very valuable maps, but cotton percale is thinner and preferred when the map will be folded into a book. Crepeline or silk was used for fragile maps, either by itself or in combination with cloth. The linings were usually adhered with wheat flour paste, sometimes with additives like formaldehyde or alum to deter pests, or glycerin to improve flexibility (LeGear 1950).
From the 1930s to the 1970s, cellulose acetate lamination, sometimes accompanied by deacidification, was a common technique for preserving maps, especially in large institutions. Maps that would be folded into bound volumes were sectioned before lamination and the folds reinforced with cloth (Minogue 1943, 36-37). Other lining and lamination techniques included pressure-sensitive cellulose acetate linings or commercially prepared dry mount linings (LeGear 1950).
===Media Stabilization===
Media degradation is not a problem unique to atlases or foldouts, but it is frequently discussed in the published literature. In some cases, degradation results from the heavy handling and page manipulation that maps and foldouts undergo. In other cases, it is due to the pigments used to hand-color printed maps.
Flat maps were sometimes protected with surface coatings like varnish, shellac, Krylon spray, or liquid cellulose acetate (LeGear 1950), and these might also have been used to protect or consolidate folded maps. Cellulose acetate dissolved in acetone was also used to stabilize water-soluble media prior to washing (Minogue 1943, 22-23).
Hand-colored maps commonly suffer verdigris damage. Large areas colored with copper-based green pigment become brittle, discolored, and extremely fragile. Damage sinks though the page and penetrates onto adjacent pages. A number of conservation publications describe the challenges and treatment options, but more research is needed. For more information, see Tsai 1992, Carlson 1997, Brostoff et al. 2011, and Albro et al. 2012.
Historical treatment for verdigris damage has included the application of alum-containing sizing solutions (Brostoff et al. 2011 and Albro et al. 2012), bleaching to restore color, and consolidation with a variety of adhesives, including poly vinyl alcohol (Blank et al. 1984) and cellulose ethers (Dobrusina et al. 2019).
==Preventive Care and Safe Handling==
Preventive care is the most effective means of preservation, and most of the recommendations for environmental control, pest management, and disaster preparedness apply equally across all library and archival materials. But a few safe handling precautions apply specially to atlases and foldouts.
Adequate space is essential. Reading room tables must accommodate large foldouts without having them extend past the edge of the table. Soft weights and book supports should be available and staff should instruct patrons in their use. A limited angle of opening can prevent damage to bookbindings. Some books with foldouts, however, must be laid flat to allow cross folds to open clear of the gutter, so staff should not rigidly insist on the use of book supports. If possible, staff should be available to assist with difficult folding and unfolding. Books with foldouts are particularly vulnerable to damage if they are carelessly closed – the foldouts should be supported as the book is closed, especially if the book is very heavy.
==Digitization Preparation==
Digitization drives the workflow of many conservation labs, and foldouts are a recurring challenge both for conservators and scanning staff. Careful project planning and education are essential. Collections with large numbers of foldouts may require significant preparation, as tears and disfiguring creases are common.
*Scanning staff should be specially trained in in safe folding and unfolding.
*Books with foldouts can be scanned in stages. The first pass scans the text pages, skipping any large foldouts. The foldouts are then individually unfolded, mended, opened out onto a support board, and then scanned. This approach minimizes handling, which can be helpful when scanning brittle or fragile pages.
==Conservation Treatment==
=== Mending ===
Foldouts are more frequently damaged than text pages because of how they must be handled – unfolded, stretched out over a surface, and then refolded. Folds are weaker than the surrounding paper and tear more easily. Foldouts are also sometimes printed on thinner paper or adhered with stiff glue. Mending techniques must accommodate these challenges. For more information about techniques and materials, see the BPG Wiki page on Mending.
Minimize the stiffness of the mend and the adhesive. Mends should be strong enough to withstand handling, but weak enough to allow the paper to flex overall and to fold along the desired line. Heavy mends may cause tears to appear elsewhere. That said, mends over folds sometimes do need to be stronger than mends on flat paper. For example, wheat starch paste or Lascaux is sometimes preferable to heat-set Aquazol 200 or 500, in order to prevent the mend from detaching from the fold as it is flexed (Kelly et. al. 2021).
Do not rush to fix problems that relieve stress. The figure on the left shows a compression crease that occurred inside a cross fold. It is not obscuring text, and if you flatten it, the crease may just reappear or relocate once the map is refolded.
The figure on the right shows a small hole that has formed at the intersection of two folds. It may be better to mend up to, but not over, the hole. Hedi Kyle described a small medieval magical charm folded into 25 panels, as discovered by Pamela Spitzmueller. The person who made the charm snipped off the corners, relieving the tension and allowing the booklet to be compactly folded (Kyle 2017). This principle can be applied during mending – by leaving intersections unmended, you may prevent the reoccurrence of the stress that led to the tear. If you do mend over the hole, make certain that the new material is flexible and compressible.
Pictured at the right is a book from 1820 in its original binding. The binder added slits in the paper to allow the foldout map to more easily escape the gutter. Although this has led to small tears at the end of the slit, the tears did not propagate into the map. If you mended those cuts, you would move the point of stress up to the internal corner, and the new tear could be worse.
Double sided mending can be a useful technique. Thicker kozo tissue can be applied to the verso, and a very lightweight tissue on the recto. For example: 5gsm and 12 gsm kozo papers, or 5 gsm and 8gsm kozo papers. These mends should not create an even sandwich, but instead one should be narrower and the other wider to avoid creating a hard breaking edge. A thin remoistenable tissue applied over the recto of a tear can smooth down rucked up edges, while a thicker and stronger tissue can be used on the verso of the map.
The order of mending can make a difference. A useful technique is to work from the inside out. When book conservators mend nested folds in gatherings, they frequently work from the inside out, mending the innermost bifolio before the outermost, and allowing the mends to dry with the bifolios closed. This allows the mends to accommodate the added bulk of the mending paper and conform to the final configuration of the gathering. Similar principles can be applied to foldouts, with a few refinements to allow the final page to both lay flat and sit closed with equal ease.
To do this, mend the valley side of the fold first, let it dry flat, and then mend the mountain side of the fold and let that dry folded. This is particularly important with water-based mending techniques where the adhesive and the mending tissue expand when wet and contract while drying. Other conservators have recommended allowing the mends to dry at a 90 degree angle (Spitzmueller 1996; Vidler 2013).
File:KellyAtlasGappingTearsBT.jpg|Gapping tears before treatment.
File:KellyAtlasGappingTearsAT.jpg|Gapping tears after treatment.
Because of the stresses on folded maps, it is not uncommon for gapping tears to significantly affect the map’s function. These can be realigned with repeated cycles of humidification and drying under weight. Realignment of text can be facilitated with temporary bridge mends using non-water soluble adhesives, like a precoated tissue that can be applied with heat or solvent (but not water). These mends stay in place during humidification and can be removed before final mending.
As discussed above, foldouts are particularly vulnerable when there is an internal corner, which occurs when the plate folds out from the head or tail. That vulnerability is the result of stress being directed at a single point. This can be mitigated by creating a rounded internal corner to distribute that stress. The image to the left shows a model that has been deliberately cut this way. When fixing tears in that area, consider trimming the mending tissue, not to a right angle, but extended beyond the paper to make a rounded corner.
A 1903 bookbinding manual, in English but translated from German, shows the rounded internal corner in an illustration, but the author does not discuss it (Adam 1903, 26-27). Another example from 1916 can be seen in William Kiesel's article about foldouts in esoteric and magical literature (Kiesel 2015). One interesting thing about these examples is that in addition to being rounded, the internal corners are offset from a fold. If a tear starts, it will run diagonally, but not immediately hit a weak fold. This makes them just a bit more resistant to damage.
=== Repositioning of Maps ===
If a foldout cannot be used safely because of how it fits into a binding, it can be removed and either rehoused or put back into the binding with improved methods. This can include making a longer guard, trimming compensation guards that interfere with the map, or changing the attachment position of the map.
The image on the right shows an 1881 atlas with a four panel foldout attached at a center fold. The tight binding did not allow the map to open flat in this configuration, and so the thin map paper tore, starting at the fold intersection. There was not space to move the map out from the gutter, so the conservator removed the map and reattached it on an edge. This allowed the map to open flat off to the side. Other conservators have described their decision to reposition foldouts, as in Karen Vidler’s 2013 series of blog posts on the “Proeschel Atlas Conservation Project” and Hannie van Herk’s blog posts on the treatment of the University of Amsterdam’s Atlas der Neederlanden (2010-2014).
=== Guarding ===
In book conservation, guarding refers both to mending the center fold of a section, and also to adding additional material to the binding edge of plates or foldouts to move them away from the gutter. It is this second definition that is the focus of this discussion.
As discussed above, there are three main types of guards. The first is a reversed v-guard or meeting guard, where gatherings are sewn through their center folds onto guards. This is a good structure to use when center folded bifolios must open all the way to the gutter, or when the attachment method must be non-adhesive. It also offers the advantage that none of the original surface is covered by a guard.
For adhesively applied guards of uniform thickness, the guard must be stiff enough to support the plate out from the gutter. This usually means a text-weight Western paper, or a very substantial kozo paper. This kind of guard was the standard choice for books with foldouts tipped to guards, starting in the 1500s. So, if a primary goal when rebinding a book is to match a historical original, this is a good choice. The challenge is that the paper in the gutter is the same paper that is getting glued to the plate – which can be hard on fragile originals and can add a lot of thickness. Some bookbinding manuals discuss thinning the plate at the point of overlap to reduce swell (Cockerell 1901, 56-62), though this would be a questionable choice for a conservator because of the loss of original material.
For guards with a flexible gap, the laminate can combine various kozo papers, or kozo paper(s) with Western paper(s). The paper weights should be appropriate to the size of the book and the thickness and quality of the plates. In general, a thicker paper is laminated to a thinner paper. The thick paper provides the necessary stiffness to lift the plates out of the gutter and to provide compensation for the thickness of the plates. A thin, strong paper provides flexibility across the gap and does not add too much bulk where it is adhered to the plate (Parks and Muratore 2021). Stiff laminate guards are particularly important for heavy foldouts or plates – a floppy guard will collapse into the gutter under the weight of a bulky foldout. Some possible combinations: laminates of 15 gsm handmade kozo, laminates of 32 gsm machine-made kozo, or that same 32 gsm kozo laminated to 85 gsm, machine-made, 75% cotton paper. The guard material must adhere well to the foldout, and strong adhesives like wheat starch paste are necessary.
=== Cloth Lined Maps ===
Before thin and strong kozo papers began to be used widely in Western book conservation, cloth was the best choice for linings and flexible hinges (Matthews 1929, 30-34), and it has a place when we treat cloth-lined maps.
Paper sticks very well to paper, but does not always stick well to cloth. Instead, it may be helpful to use cloth laminate guards to hinge cloth-lined maps. To prepare the guards, first size thin aerocotten by brushing thick A4M methylcellulose (3-4% w/v in water) onto both sides of the cloth, and then let the cloth air-dry, smoothed out on polyester sheets or Plexiglass. This makes the dried cloth a little stiffer, and much easier to handle and cut to size. Laminate the cloth with Western paper, leaving a flange of cloth off to one side. This flange is then adhered to the map, with a small gap between the plate and the laminate to allow flexing. A space-filling adhesive like PVAC or PVAC-methylcellulose mix works well for adhering cloth guards to (non-original) cloth linings. The cloth is flexible and strong, and the stiff laminate positions the plate away from the gutter.
===Partial Tipping===
The usual method of applying guards to plates is to fully adhere the overlapping parts. Partial tipping on the other hand, is when the guarding material is left unadhered along the free edge to provide a softer transition between the three layers of guard-adhesive-plate and the single layer of the plate . This is similar to the feathered edges of kozo paper used in paper mending. When using a thin kozo guard, a feathered edge may be best. When using a thicker kozo or Western paper guard, partial tipping can be useful and is much more efficient than trying to pare the edges of each paper hinge. Note that partial tipping should not be done at the binding edge of the plate. If failure occurs there, we want to have it happen in the guard, not in the plate. Partial tipping can be seen occasionally in original bindings dating back to the 17th century. It was sometimes done intentionally, and sometimes was an accidental byproduct of how binders glued things.Partial tipping can also be useful as the guarding material approaches a cross fold. These are very vulnerable areas on a map because conflicting mountain and valley folds must pop away from each other. This is especially true near the gutter of a book where the opening is restricted. Partial tipping at this point allows the map to reshape itself more gently, over a larger area.
In the image to the right, the map was probably originally glued right up to the fold, but has popped up off the guard through use. This is another example of how a map has relieved itself at a stress point. Dabbing a little glue in there to “fix the problem” would be a mistake.
Partial tipping does create a potential point of delamination, but with good quality adhesive and paper, this is not a significant concern. Cloth-to-cloth connections, however, tend to delaminate easily, and so partial tipping should not be used. Cloth-to-cloth connections are also most likely to arise when guarding cloth-lined maps, which tend to be very robust and unlikely to crack along a breaking edge.
=== Resewing and Rebinding ===
The choice to take a book apart and rebuild it is not one to take lightly. First of all, this choice inevitably destroys a portion of the material history of the object. Even when the structure is not original, there may be interesting provenance, use, or cultural information represented in the existing binding. Secondly, rebinding and the associated removal of thread, adhesive, linings, guards, etc. always poses some risk to the object. Skill and experience mitigate, but cannot eliminate those risks. And, rebinding is very time-consuming, especially when you add in guards, hinges, and compensation strips. Despite this, rebinding a guarded structure is sometimes the best way to resolve structural problems, and can allow a volume to be handled and used safely.
To help make the work of guarding multiple pages more efficient and consistent, jigs are essential. A variety of straightedge widths can make quick work of precutting and folding guards. Brass spacers can ensure even and consistent distancing of plates from their compensation. And a template or tray of binder’s board can allow each plate to be positioned on its guard so that the heads and fore edges are well-aligned (Bainbridge 2012).A jig called the “Atlas Guard-O-Matic” was designed to facilitate partial tipping. To construct it, weld together three pieces of Mylar, forming a lower base layer and two upper flaps, with a ¼” gap between them. Place the guard into the sleeve so that the area to be glued is exposed and the free edge of the guard is masked by Mylar. Apply adhesive, remove the guard from the sleeve, and place the foldout on the guard, leaving just the edge of the guard unadhered.
Rebinding a book includes making a lot of choices that affect how it opens. There needs to be a careful balance between the flexibility of the materials, the width of guards, and the pliability of the spine. The width of the guards should be proportional to the size of the book, and larger and thicker books need wider guards.
To give a sense of the variation, a large atlas (24½” tall and 2½” thick) with cloth-lined, center-attached maps that unfolded out from the head and tail, was rebound with cloth-laminate guards that extended 1½” from the gutter, had a ¼” cloth gap, and then hinged to the maps with a ½” overlap. An atlas with similarly sized pages, but 1” thick and with center-attached bifolios, was rebound with laminate kozo paper guards that extended 1” from the gutter, had a ¼” single-layer kozo paper gap, and then hinged to the maps with a ½” overlap. Smaller books have received ½ - ¾” wide guards and 1/8 - ¼” wide gaps.
Each book is different, and some may need to open more than others because of their paper qualities or how the plates unfold. The sewing method and spine linings of course have an effect on the opening. In general, avoid oversewing or excessive spine linings, because the guards should fan out at the spine and assist with the opening of the plates.
A normal order of assembly would be:
# Make oversize guards
# Fold them along the spine edge
# Trim the excess width
# Form gatherings, press
# Adhere the plates so that everything is aligned to the head
# Trim excess guard length at the tail
# Sew, then round and back
However, it is also possible to sew the guards together and even round and back before attaching the plates, as is sometimes done in production bindery work (van Herk 2010-2014). This can allow for edge decoration of the guards and avoids the problem of getting very large books in and out of a job backer.
When you do get to sewing, there are some more challenges. For large books and books with foldouts, it can be difficult to support heavy pages while opening the text block to the fold. In addition, the heavy pages can collapse at that second hinge and make positioning difficult. Conservators have come up with all sorts of clever ways of supporting oversize pages using magnets, wire, binder’s clips, or stiff boards (e.g. Peachey 2019; Avery 2019). If the structure of your book permits, the easiest solution to this problem is to position the short compensation guards consistently to one side of the sewing. If you then sew from the correct side, you only need to lift the guards rather than the entire sheet. Of course, some books have plates adhered to both sides of the guard, and you have to figure out some way of suspending the pages while you sew.
When resewing volumes with cloth-lined maps, bifolios sometimes cling to their neighbors through cloth-to-cloth friction, making it difficult to jog pages to the head or even shift a gathering into position for sewing. This problem can be solved by placing a sheet of glassine between the pages when necessary to shift them, and then removing the glassine to lock the pages into position.
As a final caution, most of the above tips were designed for text blocks with guards of matching widths and fairly consistent structures. Guards are designed to push pages out past the gutter of the book and must be stiff enough to hold the page there without collapsing. The placement of that stiff material can cause problems when neighboring, unguarded pages or endpapers must flex against it. Binders must consider the book both as individual guarded leaves, but also as a moving system.
For books with many bifolio pages on guards, there is a tendency to end up with a wedge shaped book, as the overlapping guards and plates exceed the thickness of the pages at the fore edge. Cockerell (1901) and Banks (1972) both discuss pressing after the plates are attached to guards to reduce the thickness of the overlap, and older books may have been beaten.
=== Encapsulation and Post-Binding ===
A final and entirely different option for rebinding is polyester encapsulation. Deteriorated plates can be encapsulated and then resewn with an otherwise strong text block, or the entire book can be encapsulated and put into a post-binding. These bindings can include foldouts, with the foldouts sectioned or intact (Ruzicka 1983). Encapsulation can be a good choice for high-use brittle books. However, encapsulated books triple in thickness and oversize atlases can become incredibly heavy. For more information, see the BPG Wiki page on Encapsulation.
==Glossary==
There are a wide variety of terms used to describe foldouts, guarded structures, and atlases. The glossary below gives preference to Roberts and Etherington’s Bookbinding and the Conservation of Books: A Dictionary of Descriptive Terminology (1982) and the Ligatus Language of Bindings Thesaurus. Other terms were adopted from sources listed in the Terminology section of the Bibliography.
;Apron
:“The extra amount of unprinted paper left to serve as the binding edge of a leaf which folds out” (Roberts and Etherington). A full apron is an apron of extended length that allows a foldout map to be fully visible when a book is closed. Note: The terms throw out, full apron, and foldout have overlapping meanings in various glossaries.
;Atlas
:A collection of tables, charts, plates, or maps.
;Compensation
:Material added in the gutter of a bound volume to compensate for the thickness of bulky material positioned towards the fore edge. Also called compensation guards (Roberts and Etherington) or compensating guards (The Language of Bindings Thesaurus). Simple strips of board or paper are sometimes called compensation stubs (Wootton, Boone, and Robb 2000; and Brown 2000).
;Composite atlas
:A collection of previously issued maps from various sources, gathered together into a binding. Also called atlas factice, Lafreri atlas, or Italian assembled-to-order (IATO) atlases. The last term was “coined by George H. Beans to describe the sixteenth-century Italian atlases assembled for clients by map publishers from a stock of separately published maps” (Woodward 1982). Composite atlas is the Library of Congress Genre/Form Term. When differently sized maps are gathered into a binding, strips of paper adhered to the map edges, or marginal strips, are sometimes added to create an even book block (Woodward 1987).
;Cross fold
:Two folds which intersect, generally at right angles (Angsüsser 2013). Also called a right angle fold in the paper industry. A French fold refers to a single sheet of paper folded into fourths using a cross fold.
;Foldouts
:“Inserts that are larger than the trim size of the book or other publication and which must be folded before insertion” (Roberts and Etherington). Also called a throw out (Glaister 1996, 476).
;Guard
:“A strip of cloth or paper on which an illustration, map, etc., may be attached and sewn through with the section, thus allowing free flexing" (Roberts and Etherington). Ligatus distinguishes between leaf guards for single leaves or bifolios, and extension guards for foldouts. Also called a conjugate guard (Woodward 1982).
;Guarded in
:"Plates which are inserted into a book without being tipped to one of the leaves of the book. The paper area of the plate is wider than the leaves of the book, the projecting part being wrapped around the fold of the section. A narrow strip of paper appears elsewhere in the book as a consequence" (Roberts and Etherington). Could also be called sewn in.
;Guarded in pairs
:"A method of securing two plates to one guard. While the positioning of the guard within the section may or may not allow for either or both sides to be located near the accompanying text material, guarding in this manner may help alleviate some of the swelling caused by the thickness of the material used for the guards" (Roberts and Etherington).
;Hooked
:The formation of a fold at the spine edge of a leaf to allow the leaf to be sewn into the binding (Glaister 1996, 233). This is called a returning guard in Brown 2000.
;Lipped
:“A method of accommodating a [foldout] that is longer than the trimmed height of the book. A portion of a leaf to be folded adjacent to the gutter margin is cut away, i.e., lipped, so that the remaining portion may be folded without buckling and creasing the binding margin” (Roberts and Etherington). Glaister calls this nibbed (1996, 343). This cutting away is discussed in bookbinding manuals (Pleger 1915, 41-43).
;Reversed v-guard
:“A folded guard … to which a section is sewn, the folds of the guard meeting in reverse. The guard consists of several strips of paper folded with the two open ends being folded back on the guard, either together or in opposite directions; the guard may be folded over in one direction on itself and the section sewn at either end, or it may be folded over in opposite directions on itself and one or two sections sewn to it, depending on the thickness of the sections and amount of sewing swell required … Also called meeting guard (Roberts and Etherington; see also continuous guard Roberts and Etherington; and meeting guard Horton 2000, 24).
;Simple fold
:A fold consisting of a single crease. The orientation can be either mountain fold and valley fold.
;Stub
:“...a strip of paper or cloth tipped to the gutter edge of a leaf to match the thickness of a flat object, such as a photo or map, mounted to the leaf. Several strips of stubbing may be needed if the mounted object is thick” (Horton 2000, 26).
:“1. That part of an original leaf which is left after most of it has been cut away from its conjugate leaf. See also: Cancel. 2. A narrow strip of paper or linen sewn between sections of a book for the purpose of attaching plates, maps, etc.” (Roberts and Etherington).
:See also “stub” in The Language of Bindings Thesaurus.
;Throw-up
:The curving of the book spine when it is opened. Throw-up helps the leaves to lie flat (Greenfield 1998).
==Bibliography==
===Conservation and Preservation===
Albro, Sylvia, John Bertonaschi, Dan DeSimone, Lynn Brostoff, Fenella France, and Eliza Spaulding. 2012. “The Papers of the Ptolemy Puzzle.” In: Papers of the XXXIst International Congress of Paper Historians 19. 123-134.
Avery, Melina and Ann Lindsey. 2019. "Repairing a 52-Pound Antiphonary at the University of Chicago." The Book and Paper Group Annual 38.
:Includes a description of fabricating book conservation equipment to fit a very oversize parchment manuscript volume. A sewing frame and press was constructed. Although not an atlas, the treatment of this book had similar challenges of resewing large pages. The cross bar of the sewing frame included magnets for supporting heavy pages.
Bainbridge, Abigail. 2012. “Disbinding Gabriel Tatton's Maritime Atlas of the East Indies” and “Rebinding Gabriel Tatton's Maritime Atlas of the East Indies.” West Dean College of Arts and Conservation blog. Accessed April 22, 2021.
:Talks about compensation guards being too long. New Western paper attachment guards were reattached to parchment maps with heat-set BEVA 371 film.
Banks, Paul N. 1972. "The Treatment of an 1855 British Paper Specimen Book." Bulletin of the American Group. International Institute for Conservation of Historic and Artistic Works 12 (2). 88-95. DOI:10.2307/3179130.
Banks, Paul N. 1976. “The Conservation of Maps and Atlases.” The 1976 Bookman’s Yearbook. 53-62.
Brooks, Connie. 1984. "The Guard-O-Matic." The Book and Paper Group Annual 3.
Conroy, Tom. 1987. “The Movement of the Book Spine.” The Book and Paper Group Annual 6.
Ehrenberg, Ralph E. 1982. Archives & Manuscripts: Maps and Architectural Drawings. SAA basic manual series. Chicago : Society of American Archivists, 1982. Available online through HathiTrust.
Kelly, Katherine S. 2021. "Conservation Treatment of Atlases, Foldouts, and Guarded Structures." The Book and Paper Group Annual 40: 44-62.
:Published version of this wiki page. Contains additional background information and details of historical binding methods.
Kelly, Katherine S., Jennifer K. Herrmann, Alisha Chipman, Andrew R. Davis, Yasmeen Khan, Steven Loew, Katharine Morrison Danzis, Tamara Ohanyan, Lauren Varga, Anne Witty, and Michele H. Youket. 2020. “Heat- and Solvent-Set Repair Tissues.” Journal of the American Institute for Conservation. DOI: 10.1080/01971360.2020.1795982.
LeGear, Clara Egli. 1950. Maps: Their Care, Repair and Preservation in Libraries. Division of Maps, Library of Congress. Washington, DC. Available online through Hathi Trust.
Miller, Ann-Marie and Lesley Hanson. 2010. “The Maker and the Monk: Conservation of the Mercator Atlas of Europe.” Journal of the Institute of Conservation (33)1. 29-39. DOI: 10.1080/19455220903509952
:Examination and treatment of a unique atlas, created around 1571 by Gerardus Mercator. Significant aspects of the examination and treatment included the presence of gypsum and verdigris degradation. Cracked and deteriorated areas were repaired with fiber stitches.
Minogue, Adelaide E. 1943. The Repair and Preservation of Records. Washington: U.S. Government Printing Office. Available online through Google Books.
Pardo, Luciano. 2003. "Restauración del Atlas Mayor o Geografía Blaviana: nuevas técnicas de intervención. (Conservation of the Atlas Major or, the Geografía Blaviana: new intervention techniques)" Revista PH 11, no. 43 (2003 Apr), pp. 89-99 Instituto Andaluz del Patrimonio Histórico, Seville, Spain DOI: 10.33349/2003.43.1521
:In Spanish. Conservation of a Spanish Blaeu 10 volume set from the University of Valencia. Treatments included surface cleaning, deacidification, resizing, rebinding, and binding repair. A dry leafcasting technique was developed to fill large areas of loss in maps with water-sensitive media.
Parks, Katherine, and Karissa Muratore. 2021. “Rebinding Two American Atlases with a Laminated Guard Structure at the Library of Congress.” In P. Engel, G. Boudalis, E. Mousakova, F. Pinzari, J. Schiro, & J. Vodopivec Tomazic (Eds.), Book conservation one philosophy - many interpretations (pp. 297–314). essay, Verlag Berner, Horn/Wein.
Peachey, Jeff. 2019. "A Simple Fixture to Hold Leaves Upright on a Sewing Frame." Peachey Conservation Blog. Accessed June 3, 2021.
Ruzicka, Glen. 1983. “Polyester Encapsulation in Signatures.” The Book and Paper Group Annual 2.
:Describes the Hollytex hinge method used for folded encapsulations.
Slawik, Abigail. 2021. "Conservation Treatment of Hendrick Doncker’s Zee-atlas from 1660; Or, How an Atlas Gets Stressed, and What Book Conservators Do About It." New York Public Library Blog. Accessed February 23, 2022.
: Conservation treatment of an oversize atlas with splitting guards. Guards were repaired with kozo and wheat starch paste.
Spitzmueller, Pamela. 1996. "A Sourcebook on Atlas Structures." Workshop notes prepared for the Andrew W. Mellon funded Advanced Conservation Workshop Series at the University of Iowa Libraries Conservation Dept. Feb. 27 - March 2, 1996, Iowa City.
Valk-Falk, Endel. 1975. "The Conservation of the Atlas-Incunabula of Francesco Berlinghieri's The Geography by Means of Pulp-Filling Apparatus." In International Council of Museums–Committee for Conservation: Preprints of the 4th Triennial Meeting Venice, 13–18 October 1975. International Council of Museums, Paris, France (1975) pp. 75/15/14-1-10.
:Treatment of a 1480 Ptolemy included removal of old linings and mends, stain reduction, leaf casting, resizing, regeneration of the iron gall ink, inpainting, and rebinding.
van Herk, Hannie. 2010-2014. “Atlas der Neederlanden.” Series of blog posts on the conservation of the University of Amersterdam’s Atlas der Neederlanden. Accessed April 22, 2021.
:Chronicles the conservation treatment of a nine volume composite atlas owned by the University of Amsterdam. Although there is an abbreviated version available in English, the entire Dutch text can be read using Google Translate. September 2010 has a nice video showing compression creases. The May 2011 entry, discusses the repositioning of folded maps on existing guards to improve their opening. September 2013 has an interesting image of how, for the facsimile rebinding, the empty guards are rounded and backed before the maps are adhered, and how a template is used to align the maps as they are adhered to the guards.
Vidler, Karen. 2013. “Proeschel Atlas Conservation Project.” Series of four blogs posts. National Library of Australia. Accessed June 9, 2020.
:Describes the conservation of an 1863 atlas. Compares English vs. German guarding styles. Splits in the cloth lined map were mended with inserts of kozo paper. Mends to folds of unlined paper maps was done at a 90 degree angle. Maps were repositioned to be farther out from gutter to improve opening.
===Cartography and Atlases===
Akerman, James Richard. 1991. "On the Shoulders of a Titan: Viewing the World of the Past in Atlas Structure." Ph.D. diss. The Pennsylvania State University. Available from ProQuest Dissertations & Theses Global.
Akerman, James R. 1995. “From Books with Maps to Books as Maps: the Editor in the Creation of the Atlas Idea. In Editing Early and Historical Atlases: Papers Given at the Twenty-Ninth Annual Conference on Editorial Problems, University of Toronto, 5-6 November 1993. Joan Winearls, editor. United Kingdom: University of Toronto Press.
:Excellent overview of Ptolemaic, Portolan, Ortellian, Mercator atlases. See also Winearls 1993.
Bagrow, Leo. 1975. A History of the Cartography of Russia Up to 1600. Wolfe Island, Ont.: Walker Press.
Fontaine Verway, Herman de la. 1971. “The Binder Albert Magnus and the Collectors of His Age.” Quaerendo 1 (3). DOI:10.1163/157006971X00149.
:Discusses “Blaeu’s regular binder”, who made both the distinctive “Dutch Atlas Bindings” and very upscale leather.
Fontaine Verway, Herman de la. 1981. “The Glory of the Blaeu Atlas and the 'Master Colourist'.” Quaerendo 11 (3). DOI:10.1163/157006981X00229.
:Discusses the distinctive “Dutch Atlas Bindings”.
Lister, R. 1965. How to Identify Old Maps and Globes. Connecticut: Archon Books
Ristow, Walter W. 1985. American Maps and Mapmakers: Commercial Cartography in the Nineteenth Century. Detroit: Wayne State University Press.
Utter, Tim and Erin Platte. 2018. “Mr. Vignaud's Maps: Unraveling a Cartographic Mystery from the Golden Age of Dutch Cartography.” Online exhibit from the University of Michigan Library. Accessed April 22, 2021.
:Describes how close examination of paper characteristics and binding evidence can allow broken atlases to be reassembled.
Van Der Krogt, Peter. 1996. "Amsterdam Atlas Production in the 1630s: A Bibliographer's Nightmare." Imago Mundi 48. 149-60.
Winearls, Joan. 1993. The Atlas as a Book, 1490 to 1900. Toronto : Thomas Fisher Rare Book Library, University of Toronto.
:Guide to an exhibition that accompanied 1993-1994 symposium, see Akerman 1995.
Woodward, David. 1982. “The Techniques of Atlas Making.” The Map Collector 18.
:Short, but rich article on the physical make-up of atlases. Includes a glossary.
Woodward, David. 1987. “The Analysis of Paper and Ink in Early Maps.” Library Trends 36:85-107.
Woodward, David. 2007. “Techniques of Map Engraving, Printing, and Coloring in the European Renaissance.” Chapter 22 in: The History of Cartography, Volume 3, Part 1. 591-610.
===Bookbinding Manuals===
Adam, Paul. 1903. Practical Bookbinding. Translated from German by Thos. E. Maw. Scott, Greenwood & Co. London. Available online through Project Gutenberg.
Cockerell, Douglas. 1901. Bookbinding, and the Care of Books, a Text-book for Bookbinders and Librarians. London: J. Hogg. Available online through Project Gutenberg.
Diehl, Edith. 1980 (1946). Bookbinding: Its Background and Technique. Two volumes bound as one. New York: Dover Publications, Inc.
Geraty, Peter. 2019. "A Manual Approach to Stiff-Board Parchment Binding. In Suave Mechanicals, vol. 5, edited by Julia Miller, 124-196. Ann Arbor, Michigan: Legacy Press.
Johnson, Arthur W. 1985. The Practical Guide to Bookbinding. New York: Thames and Hudson.
Matthews, William. [1929]. Bookbinding; a Manual for Those Interested in the Craft of Bookbinding. New York: E. P. Dutton and Co. Available online through Hathi Trust.
Minter, Bill. 2015. “The Meeting Guard: Its Use Historically and Its Use in Fine Bookbinding, Conservation and Artist Books.” Handout from 2015 Guild of Book Workers Standards of Excellence.
Nicholson, James B. 1856. A Manual of the Art of Bookbinding. Philadelphia: Henry Carey Baird. Available online through Hathi Trust
Pleger, John J. 1915. Bookbinding and Its Auxiliary Branches: Part II: Punching, Crimping, Cycletting, Pamphlet and Quarter Binding. Inland printer Company. Available online through Google Books.
United States Government Printing Office. 1962. Theory and Practice of Bookbinding. United States Government Printing Office Training Series. Washington, DC. Available online through Hathi Trust.
:p. 183 contains a short, but useful description of how compensation is inserted into bindings 
Zaehnsdorf, Joseph W. 1880. The Art of Bookbinding. London: G. Bell & Sons. Available online through Google Books.
Zaehnsdorf, Joseph W. 1890. The Art of Bookbinding: A Practical Treatise. London: G. Bell & Sons. Available online through Google Books.
===Folding===
Angsüsser, Stephan. 2013. “Map Folding Techniques in the Digital Age.” Proceedings of the 26th International Cartographic Conference. Dresden, Germany, 25–30 August 2013.
Boyle, Lucinda. 2015. "Reproduction of Maps - Folding Strategies." The History of Cartography, Volume 6. 1336-1338.
Kiesel, William. 2015. “Folding Plates in Esoteric Literature.” The Journal of the Book Club of Washington 15 (1). 41-60.
Kyle, Hedi. 2017. “The Fold: Evolution, Function, and Inspiration.” In Suave Mechanicals, vol. 3, edited by Julia Miller, 160-195. Ann Arbor, Michigan: Legacy Press.
Monmonier, Mark. 2017 “Folding, Unfolding.” In: Patents and Cartographic Inventions. Palgrave Studies in the History of Science and Technology. Palgrave Macmillan, Cham. DOI: 10.1007/978-3-319-51040-8_4.
===Media and Color===
See also Miller and Hanson 2010.
Blank, M.G., Dobrusina, S.A. and Lebedeva, N.B. 1984. "A Search for Procedures for Restoration and Stabilization of 16th and 17th Century Netherlands Atlases Damaged by Green Paint." Restaurator 6:127-138. DOI: 10.1515/rest.1984.6.3-4.127.
Brostoff, Lynn, Sylvia Albro, John Bertonaschi, and Eliza Spaulding. 2011. “The Relationship between Inherent Material Evidence in Cultural Heritage and Preservation Treatment Planning: Solving the Ptolemy Puzzle, Part II.” The Book and Paper Group Annual 30.
Carlson, Lage. 1997. “An Interim Treatment for Paper Degraded by Verdigris.” The Book and Paper Group Annual 16.
Dobrusina, S. A., Podgornaya, N. I., Volgushkina, N. S., and Tsitovich, V. M. 2019. “Preservation Evaluation of the Collection of Western European Engraved Atlases of the 16th-18th Centuries. The Electronic Passport of the Atlas’s Condition.” Conservation Update – Publication of the ERC, 1/2019 (April).
Federici, Carlo and Margaret Hey. 1975. “Problems Involved in the Restoration of a Mercator Atlas.” In International Council of Museums–Committee for Conservation: Preprints of the 4th Triennial Meeting Venice, 13–18 October 1975. 1-19.
:Discusses verdigris deterioration in 1623 atlas.
Helm, Sarah, Erin Platte, and Grace Rother. 2018. “The Geography of Colorants.” Online Exhibit by the University of Michigan. Accessed June 3, 2021.
Stillo, Stephanie Elizabeth. 2016. "Putting the World in Its “Proper Colour”: Exploring Hand-Coloring in Early Modern Maps." Journal of Map & Geography Libraries 12:2, 158-186. DOI: 10.1080/15420353.2016.1146200.
Tsai, Fen-Wen. 1992. "Sixteenth and Seventeenth Century Dutch Painted Atlases: Some Paper and Pigment Problems.” In Conference Papers, Manchester 1992, ed. Sheila Fairbrass (London: Institute of Paper Conservation, 1992). 19–23.
:Study of paper and pigment deterioration problems in a 1573 Ortelius atlas and non-map pages from a 1658 Mercator/Jansson atlas. Both samples had white areas occurring on a darker (degraded) background. Damage to the paper and azurite blue pigment of the Ortelius atlas was tentatively attributed to alum from surface sizing of the map prior to watercoloring.
Zagorski, Melissa. 2007. The Geography of Significant Colorants: Antiquity to the Twentieth Century. Thesis from George Mason University. Accessed 23 September 2020.
===Terminology===
See also Angsüsser 2013, Woodward 1982.
Brown, Barbara, comp. 2000. “Glossary of Terms for the Photographic Album Survey” in Conservation of Scrapbooks and Albums: Postprints of the Book and Paper Group/Photographic Materials Group Joint Session at the 27th Annual Meeting of the American Institute for Conservation of Historic and Artistic Works. 85-92. Washington, DC: AIC.
Glaister, Geoffrey A. 1996. Encyclopedia of the Book. 2nd edition. Oak Knoll Press: New Castle, Delaware.
Greenfield, Jane. 1998. ABC of Bookbinding. New Castle, DE: Oak Knoll Press.
Horton, Richard 2000. “” in Conservation of Scrapbooks and Albums: Postprints of the Book and Paper Group/Photographic Materials Group Joint Session at the 27th Annual Meeting of the American Institute for Conservation of Historic and Artistic Works. 21-28. AIC, Washington, DC.
Ligatus Language of Bindings Thesaurus.
Roberts, Matt T. and Don Etherington. Drawings by Margaret R. Brown. 1982. Bookbinding and the Conservation of Books: A Dictionary of Descriptive Terminology. Washington DC: Library of Congress. Available online through CoOL.
Wootton, Mary, Terry Boone, and Andrew Robb. 2000. “The Structure’s the Thing! Problems in the Repair of Nineteenth-Century Stiff-Pages Photograph Albums” in Conservation of Scrapbooks and Albums: Postprints of the Book and Paper Group/Photographic Materials Group Joint Session at the 27th Annual Meeting of the American Institute for Conservation of Historic and Artistic Works. 37-44. Washington, DC: AIC.
==History of This Page==
This page was created in 2021 by Katherine Kelly as part of her presentation at the AIC Annual Meeting, "Conservation Treatment of Atlases, Foldouts, and Guarded Structures". Further updates and improvements are welcome.
Category:Materials and TreatmentCategory:Book & Paper