The following notes may be regarded as supplying a summing up of the characteristics aud properties of the pigments used in sign-painting. Burnt sienna is a rich transparent red-brown earth used for glazing over gold leaf and shading. It works well on gold leaf when mixed with a small quantity of ox-gall, and should be thinned with copal varnish, not turpentine; gold size may be used as a drier. It dries better than raw sienna, and is very permanent, as it is not liable to change by the action of light and oxygen, nor by damp and impure air. Burnt umber is a burnt Italian ochre. It dries well in oil, and is therefore often used as a drier. It is very permanent, and is sometimes used instead of Vandyke brown. Emerald green, which is, perhaps, the sign-writer's special green, is a copper green upon a terrene base, very useful for brilliant work. It has not much covering power, and is a bad drier in oil, and therefore requires gold size or patent driers. It retains its colour well. The tube colour is the best. Flake white is a very pure white, not likely to discolour; it is on this account generally used as a finish over previous coats of white-lead. Green lakes are powerful colours, but not per manent. They may be purchased in bulk ready ground in oil, or in tubes.

Indian red - peroxide of iron-makes pleasant tints with white, is permanent, and possesses great body. It may also be used as a ground colour, or as a shade tint with vermilion. For a quick-drying ground colour it may be mixed with turpentine 4 parts, varnish 1 part. Indigo possesses great body, and is a. good glazing colour. It is not very durable, and is injured by impure air. Ivory black is made by placing ivory dust in a covered crucible exposed to a great heat. An inferior colour known as bone black is made by treating bones in a similar way. Ivory black, the deepest and purest of the blacks, being somewhat hard, requires very careful grinding, and unless ground very fine is useless. It is best ground in turpentine, and diluted for use with turpentine, gold size, and a little varnish. In drying it will become dull, so that it should not be used unless it is afterwards to be varnished. If thinned down too much with turpentine it will not bind, so that when the varnish is applied it will rub off on to the rest of the work and spoil the whole. Ivory black, when purchased unground, resembles "drops, aud is sometimes called " drop black," but bone black is prepared in the same way. Lemon and orange chromes, when of best quality, are chromates of lead.

They are brilliant, have good body and covering power, and make good tints when mixed with white. When used in oil they must be protected by varnishing, especially it exposed to impure air, which in time will turn them black. They make so-called gold colours, and must on no account be intermixed with Prussian and some other blues in making greens, as chromate of lead will destroy these pigments. The yellow chromes are made in three shades, known as Nos. 1, 2, and 3; the No. 4 shade is the orange chrome, a deep rich colour. The shades are varied by increasing the chromate for deep orange, and lessening it for the pale yellows. These colours are injured by damp and impure air, sulphur fumes, and hydrogen; but the orange chrome is said to last better-than orange oxide of lead. The chromes require skilful handling. Prussian blue is a good working and staining colour, and a quick drier. Raw sienna is rather an impure yellow, but has more body than the ochres ami is also more transparent. By burning it becomes burnt sienna, which lias the same properties, lime umber is a good drying colour that does not injure colours with which it is mixed.

Ultramarim , when perfectly pure, is most expensive, but the sign-writer generally uses French ultramarine, an inferior product, which will, however, stand when protected with oils and varnish. It may he deepened with vegetable black, ami when mixed with white makes a pure tint. Vandyke brown is a rich, deep, transparent brown, and is a permanent colour good for glazing and lor " markings" on gold. It is a bog earth, and not a very good drier. Vegetable black, which has taken the place of lamp black, is a light powder, and requires no grinding. Patent driers ma;,' be added, and it maybe used on unvarnished work. Venetian red is cheap hut permanent, and must be procured ready ground in oil. It is useful as a ground colour. Ver-milion can be had as a fine dry powder, free from grit, and is a very brilliant colour in oil. The best quality only is permanent, and that is a sulphuret of mercury. Chinese red, or vermilion, is of a deep crimson tone, but has bad covering power, and, unless well protected, will soon fade under the action of light and impure air.

White lead - one of the most frequently used colours and also one of the most faulty - is made by suspending rolls of ordinary thin sheet lead over malt vinegar or pyroligneous acid, in close vessels, the evaporation from the acid being kept up by a steam bath underneath. The lead is thus reduced to a white powder ready for being ground with linseed oil into a paste. White lead improves by keeping, and for good work should be stocked for at least twelve months after purchase. Very pale and old linseed oil should be used in the thinning, otherwise it will probably soon discolour. It is, how-ever, about the best pigment for preserving wood, etc., from the effects of the weather. Zinc white is an oxide of zinc, but it does not possess so much covering power as white lead. It, however, does not discolour, and is a very pure pigment. Yellow ochre is not a very bright colour; it is best purchased in tubes, otherwise it is not thoroughly ground. It is an earth found in most countries, and is of all shades, from the warm yellow of the Oxford ochre to the pale straw 3rellow of the French earth: the latter is often used for "old gold" shades, etc.

The ochres are not liable to change through any chemical actions, and may therefore be considered permanent.