Bone folder (left) used with a straight edge (right) to form a crease in a custom archival enclosure. (Courtesy of Karen Walter, Weissman Preservation Center, Harvard University)n.a shaped tool used in archival settings to fold papers and card stock, to tear mending strips, and to crease polyester enclosuresJohnson 1978, 24Bone folders are made from ivory, bone, hardwood or plastic. A very long folder with blunt ends and one thinned side is used for folding and cutting paper. The ideal shape for most work is 160 mm long and 25 mm wide (6 X 1 in.). It should be smooth and heavy at the bottom, narrowing slightly to a blunt point at the top. A heavy folder filed at each end to blunt points is necessary for box-making. For finishing and fine work about 120 mm (4 ¾ in.) long with a very long and fine point is used. A light thin folder with a fine point at one end and a chisel shape at the other is used for positioning onlays and inlays of leather.Young 1995, 20Bonefolders. These are shaped pieces of bone, as the name implies. They are fashioned in a variety of sizes and shapes and have many uses. A large one is useful in the folding of paper, smoothing out slight wrinkles when pasting and gluing; and a small one is helpful in turning corners, setting headcaps, and in drawing off lines to be tooled.Jefferson and Coleby 1991, 32TOOLS AND MATERIALS REQUIRED . . . Thick bone folderRitzenthaler 2010, 468Supplies and Equipment . . . Bone folderNARA 2016eBone Folders ¶ Smooth, thin tool made of bone with tapered or pointed ends, used to make strong creases in file folders.NEDCC 2018, 4Using the point of the bone folder on the surface of the card stock, score the card along the edge of the ruler as if you were drawing a line with a pencil. Press the point of the bone folder into the card and pull it along the edge of the ruler, creating a groove.NEDCC 2018, 5When constructing polyester jackets, you will need a straight-edge, a bone folder, and either scissors or a mat knife.
Bone folders most commonly are made from ivory, bone, hardwood, or plastic. The smooth tool is wider at the bottom and narrows to a blunt point at the tip.