Board Shear, American 1870s
When casebinding became the norm for edition binding in the 1830s, binders sought an easier way to trim cover board. These boards, made of layered waste paper or paper pulp sandwiched between two sheets of paper under high pressure, is difficult to trim by hand. The fibers in the paper can shred, or the cut go askew. In an industry increasingly concerned with the ability to create identical books with cases made with bookboard and the less-forgiving fabric that covered it, a clean, clear cut was essential.
Thus the board shear (1) became a fixture in the bindery. In casebinding, covers are produced by covering bookboard in fabric, shaping and decorating them as necessary, and then gluing the text block into the case by its end-papers. This process was done by hand until the 1890s. The board shear, which could produce consistent, smooth, and square cuts on even the densest bookboard, was indispensable.
Like scissors, the board shear has two blades: the stationary blade forms the edge of the cutting table, with the moving blade mounted on the cutting arm. Because of the weight of the moving blade the cuts are clean and sharp, without shredding. The gauge bar can be set to the needed depth, with the coverboard braced against it, ensuring that all boards could be cut to the same size.
Like scissors, the board shear uses two blades. The stationary blade forms the edge of the cutting table with the moving edge mounted on the cutting arm. The gauge bar could be set to the needed depth so that all boards could be cut to the same size. Once the gauge is set, the board is measured as it is cut: each piece will be the same as the last (2).
1) ABM’s board shear was a gift of the estate of Bruce Robert Levy, a bookbinder in Grass Valley, California. It is still in use in the museum to cut board for display and to cut bookboard whenever it is needed.
2) Jacob Abbott describes the board shear in use in the Harper Brothers’ steam-powered factory in The Harper Establishment, or How the Story Books Are Made, New York: Harper Bros., 1855. It can be found at https://archive.org/details/harperestablishm00abbo/page/n7/mode/2up.