2. Coloured inks should be mixed upon a slate or marble slab, by means of the muller, and never upon an iron or other metallic table. The table, before mixing, should be thoroughly clean, and perfectly free from the slightest soil or trace of other inks. 3. For working coloured inks, the roller should not be too hard, and should possess a biting, elastic face. When change of colour is required, it should be cleaned with turpentine, and a moist sponge passed over the face, allowing a few minutes for the roller to dry before resuming its use. For bronze printing, the roller should have a firm face, or the tenacity of the preparation may destroy it; yet it must have sufficient elasticity to deposit the preparation freely and cleanly on the type. 4. Various shades may be produced by observing the following directions:— BRIGHT PINK INK.—Use carmine or crimson lake. DEEP SCARLET.—To carmine add a little deep vermilion. BRIGHT RED.—To pale vermilion add carmine. DEEP LILAC.—To cobalt blue add a little carmine. PALE LILAC.—To carmine add a little cobalt blue. BRIGHT PALE BLUE.—Cobalt. DEEP BRONZE BLUE.—Chinese. GREEN.—To pale chrome add Chinese blue; any shade can be obtained by increasing or diminishing either colour. EMERALD GREEN.—Mix pale chrome with a little Chinese blue, then add the emerald until the tint is satisfactory. AMBER.—To pale chrome add a little carmine. DEEP BROWN.—Burnt umber, with a little scarlet lake. PALE BROWN.—Burnt sienna; a rich shade is made by adding a little lake as above. 5. GOLD PREPARATION. Print as with ordinary ink, then put on the bronze powder with a broad camel-hair brush; allow the impressions to remain a short time for the preparation to set, then clean off the superfluous bronze: the impressions will be much improved if passed through rollers. HOW TO MULTIPLY COLOURS. A printer who has on hand a stock of yellow, carmine, blue, and black inks, may produce other colours and shades by intermixing as follows:— Yellow and carmine, mixed, will give Vermilion. Carmine and blue Purple. Blue and black Deep blue. Carmine, yellow, and black Brown. Yellow and blue Green. Yellow and black Bronze green. Yellow, blue, and black Deep green. Lighter shades may be obtained by adding proper proportions of white ink. CONTRAST OF COLOURS.