No. 4.—(A London formula.) Dry white lead, ground stiff in turpentine, 1 1/2 lbs.; ochre, or English filling, ground stiff in turpentine, 4 lbs. Mix the two and add 1/2 lb. of tub lead. Add 1 pint of japan gold size and about 1/2 pint of the bottoms of wearing varnish. Reduce with a little turpentine if necessary. This is a very durable and elastic 'stuff.
No. 5.—(M. Arlot's formula.) "Grind separately lump white lead with essence of turpentine, and do the same with unwashed yellow ochre; then mix the two pastes in the proportion of 3/4 of white lead and 1/4 of ochre. Allow the mixture to stand exposed to the air or to a gentle heat in order to evaporate the excess of liquid, and add gradually small portions of good drying oil, taking care to stir and beat the mixture well with a brush, as in distemper painting. The paste thus acquires more body." Concerning this 'stuff the author adds: "It is possible with this composition to give three coats in a day's work, but after the last coat we must wait 48 hours for drying."
No. 6.—English filler 3 lbs.; keg lead 1 lb. Rubbing varnish and japan, half and half, to make a stiff paste. Thin with turpentine.
No. 7.—English filler, mixed stiff with rubbing varnish, 1/2; japan 1/2. Thinned with turpentine.
Probably genuine English filler has but few, if any, equals, and certainly no superiors as a roughstuff pigment. It polishes down very close and compact as to texture, giving a glass-like, non-porous surface. It requires less lead than other fillers, because of which property it was specially mentioned as excluded from formulas 2 and 3. It does not surface down as easily as some of the American fillers, a fact that has probably limited its use largely.
In using keg lead for roughstuff, a moderately stiff ground lead is advisable. A lead ground in an excess of oil will necessitate washing in turps to expel a portion of the oil, if the proper proportions of ingredients would be maintained. In mixing roughstuff, it pays to be exact as to proportions and quantities. Use first-class materials, varnish, japan, etc. Slops and refuse from varnish and japan cans are to be avoided. They leave the user in a state of uncertainty as to the composition of his 'stuff. If made in considerable quantities at a time, the pigment should be stored in a tight, dust-free receptacle and well covered with water or turps, else it will very soon become gummy and unsuitable for good work.
Paint Strainer.
The chief mission of roughstuff is to enable the painter to get a firm, hard, level surface. It requires putting on with a good brush, and a skilled and painstaking wielder of the tool. Roughstuff should be carried to a surface a little heavier in body than ordinary paint, but its spreading and flatting property should in no wise be made sluggish and "ropy" by the absence of thinning mediums. Better an additional coat of 'stuff than one coat less because of the excessively thick coats used. Roughstuff, like all quick setting pigments, needs to be applied, brushed out, and leveled quickly under the brush, so that brush marks may not intrude or uniformity in depth of film be wanting. Use a brush suited to the size of the panel; likewise a brush with a softness and fineness of point and sufficient elasticity to insure, if properly wielded, freedom from brush marks. Too heavy a pigment is no more a prolific cause of brush marks than a too nearly worn out brush. If the first coat of 'stuff is laid on the panel with horizontal strokes of the brush, let the second be laid with vertical ones, and vice versa. On a well-surfaced job, four coats should suffice. Where greater inequalities of the surface exist, more coats will be necessary. But it is an established maxim in both the practice and theory of carriage painting that the less roughstuff used upon a surface, granted that the quantity accords perfectly with the needs of the surface, the greater the durability of the paint and varnish structure.