A window mat is the customary mount for artworks, posters and photos. A mat is composed of a top sheet with a window. The window permits the art to be 'set off' to best advantage, provides protection for the art edges, and allows a small space between the art and the perspex (or glass). The backboard protects it from handling and isolates it from surrounding materials.

Because most of our aluminium frames are not deep (8-9mm) it is up to you whether you want to hinge the window and backboard as they should be held well within the frame. The advantage though is it does keep the window and backboard together if there is any movement or if you change frames.

Historically, museum-quality mats for works of art were expected to be made of rag fibers, that is, cotton or linen. Today ragboard is still favored by museums, but it is very expensive and some lignin-free, wood-derived boards are now often used. Mat boards of either type are usually buffered with an alkaline material to neutralize any acids they may absorb as they age. We only use acid free mats and backboards that typically come from the U.S.A.

Four-ply board is the thickness most often used for matting. Boards heavier than four-ply are available from conservation suppliers, but we don’t carry them. At justframekits we take a pride in our work, but we are not conservation framers. We produce the best frame kits we can, for the best price we can, using high quality materials.

Hinging is the customary way to mount an object in a window mat. The artwork is hinged, with acid free paper. Conservation framers usually use Japanese paper and starch paste, but it is painful to apply. We use (and supply with orders) an acid free German made self adhesive tape.

In conservation framing the artwork is usually hinged to a separate (back) mat board. We do not supply a back matboard, because it would significantly increase your cost but we are happy to quote if you want one. Our (supplied) backboards are made of clay coated foamboard and are acid free, and you can attach to them if you want to. The reason the 'hinged sandwich' is used for conservation framing is because they are often very valuable works. Most of our customers just hinge from the mat itself. It is up to you which method you choose. By hinging to the backboard, it keeps your art stationary when a mat is opened and could prevent damage by hooking it in the window. It also means the back of your art is not exposed or laid directly on your work surface.

Whichever method you use, the most common method for attaching your art is the T hinge. As shown in the Figure below part of the hinge is attached to the object and part to the matboard or backboard. Hinges allow the artwork to be removed easily from the board if that becomes necessary. Just hinging from the top allows the artwork to hang, without chancing wrinkles.

Further reading

Mat board and more

Readymat - Mastering the Casual Hinge in Seven Simple Steps

Northeast document conservation centre

Frame destination

Altos EZ Mat