Page:Cyclopedia of Painting-Armstrong, George D (1908).djvu/415

Rh should be kept in an earthenware pan covered with a wet cloth. Putty which has become hardened may be made again fit for use by warming and beating it up, and kneading it whilst in that condition. For particular purposes, as for fanlights, iron-framed greenhouses, and other places where the lap or hold is very narrow, a little white lead may with advantage be added. To color putty, mix red ochre, lamp black, or other color with the whiting.

Putty, To soften. Slake some quick stone lime in water, and add one-third of the quantity of pearlash, make the mixture about the thickness of paint. Apply it with a brush to the putty on both sides of the glass, and leave it on for a day or so, the putty will then have become so softened that it may easily be removed with a glazier's knife, and the pane of glass may then be taken out.

Size, To make. Practically, size is merely glue so much diluted with water that it does not for a very long time harden in the mass, but preserves a jellified condition, and is thus sold in barrels. A better kind is however supplied, made into very thin square cakes like glue, which is principally used for sizing wood which has been stained, or for refined purposes. Parchment size is the best for distemper colors, and is made in the following manner: Place a quantity of parchment cuttings in an iron kettle, cover them with water, and allow them to soak thoroughly, from twenty-four to thirty-six hours will be required for this purpose, and should the water have been absorbed, more must be added. The whole is then to be boiled for about six hours, during which the scum which rises must be removed. It is afterwards to be strained through a coarse cloth. Size prepared in the following manner will keep good for several weeks: Dissolve 3 or 4 ounces of alum in boiling water, and add the solution to every pailful, boil and strain the size a second time, and set in a cool place.

Size, Glove-leather. Take $1/2$ pound of the cuttings of white glove-leather, put them into water and allow them