Pattern Varnish
Usually wood patterns are made from white straight-grained pine, which, while it is an excellent material for working and keeping its shape, is very soft and porous. If such patterns are moulded from without any subsequent treatment, the pores soon fill with sand-dust, which adheres firmly to the moulding-sand and leaves a scarred surface on the mould. To prevent this the patterns should receive a good coat of varnish made from one pound of shellac digested in one gallon of alcohol with as much lamp-black as will color it. After this has thoroughly dried, rub off with fine sand-paper and apply another coat of the varnish slightly diluted with alcohol. See VARNISH.