All our picture frames are produced on demand at our facility in Spencer MA using our exclusive Quadro Frames molding system. Moldings are custom extruded to our specifications and consist of ABS plastic with a metallized mylar finish, they are virtually indistinguishable from a metal frame at a fraction of the cost. Backing panels are 0.10 inch thick MDF (Medium Density Fiberboard) - NOT cheap corrugated cardboard. Front panels are 0.040" thick optically clear PET plastic with an opaque and/or blue protective peel away film applied to both sides. While assembling your frames make sure to peel off the protective film from BOTH sides of the plastic panel. The frames dimensions refer to the PANELS so that media of the specified size will fit in the frame. The external dimensions of the frame are 3/8 inch larger than nominal size. The visible image size (accounting for the overlap of the moldings over the panels) is 3/4 inch less than the nominal size. The moldings are side loading and in additional to the panels provided will accomodate 3/16 inches of media thickness. This is sufficient space for an image as well as a double standard thickness matteboard. All components are manufactured to the highest tolerances for a picture frame of seamless fit and finish. Assembly is required but consists simply of snapping four (4) corner connectors onto the moldings, no tools are required the frames literally snap together in seconds. The corner connectors fit onto the back side of the moldings and are not visible from the front or sides. The frames are designed to hang from the corner connectors, which include an arc shaped sawtooth pattern for fine levelling adjustment on the spot! These classic contemporary style picture frames are an excellent choice for framing virtually any image with a professional gallery look.