Painters' and Glaziers' Putty is made with whiting (see p. 254) and oil. The whiting is reduced to very fine powder, carefully dried, passed through a fine sieve (about 45 meshes to the inch), mixed with raw linseed oil into a stiff paste, well kneaded, left for 12 hours, and worked up in small pieces till quite smooth.

For particular purposes, such as in fanlights, where the lap or hold is very narrow, a little white lead may be added with advantage.1

Hard Putty may be made by substituting turps for part of the oil. Very Hard Putty, from oil, red lead, white lead, and sand.

Soft Putty, from 10 lbs. whiting, 1 lb. white lead, mixed with 1/2 gill best salad oil and enough boiled linseed oil to bring it to the proper consistence.1 The harder kinds crack unless they are soon painted.

Plasterers' Putty (see p. 246).

Thermo-Plastic Putty contains tallow, which keeps the putty pliable, so that it is not loosened by the expansion and contraction of large panes of glass under changes of temperature.2