Fig. 13.—Position of register marks.

Fig. 14.
Register marks.

Fig. 14.
Register marks.

The corer mark, ABC, is made by cutting from A to B and B to C, with the knife held perpendicularly, and its flat side against the line, then the shaded portion is cut with a flat chisel, sloping from the surface of the block at AC to a depth of about 1/16 inch along AB and BC. The straight notch, EF, is similarly cut, first with a perpendicular knife along EF, and then the shaded portion is chiselled sloping down to the line EF.