(3) Wet with iron liquor and rub with a piece of iron; then oil, or give a dressing of composition made by melting 2 oz. black rosin and adding 3 oz. beeswax. When thoroughly melted, take from the fire, and add 1/2 oz. fine lamp-black which has had 1/2 dr. Prussian blue mixed with it; thin with turps just before it gets too cold. Apply a coat of this with a rag, and polish with a soft brush.
(4) Ball Black. For harness leather straps, this is made of 1/4 oz. isinglass, 1/4 oz. indigo, 4 oz. logwood, 2 oz. soft soap, 4 oz. glue, softened, and 1 pint of vinegar; the whole is mixed, warmed, strained, and allowed to cool, when it is ready for use.
(6) Patent Leather Black. Mix together £ lb. each of ivory black, purified lamp-black and pulverized indigo, 3 oz. dissolved gum-arabic, 4 oz. brown sugar, and 1/4oz. glue, dissolved in 1 pint water; heat the whole to boil over a slow fire, then remove and stir until cool, and roll into balls.
(7) Vinegar Black. This is the most simple and useful colouring liquid for the trimming shop for blacking leather straps. To make the simplest, and without doubt the best, procure shavings from an iron turner, and cover them with pure cider vinegar; heat up and set aside for a week or two, then heat again and set in a cool place for 2 weeks; pour off the vinegar, allow it to stand for a few days, drain off, and cork up in bottles. This will keep a long time, and while producing a deep black on leather, it will not stain the hands.
(8) Vanadian Black. This process is due to Sorensen, of Sweden, and he thinks that it will make black dyeing on leather easier, cleaner, and more durable than that obtained by present methods. The leathers to be treated by this process ought to be tanned with nut-galls, and consequently contain gallic acid or its derivatives, which give a black colour on treatment with salts of vanadium. The author admits as well known the compounds of gallic acid with which vanadium ought to produce a black dye, as well as the salts of vanadium which are commonly used for this purpose. It is of no importance what particular time after the tanning is chosen for dyeing the leather black. The dyeing is effected by simply applying over the surface a solution of a suitable salt of vanadium, so that the chemical reaction may take place within the texture of the leather. Thus he recommends as very efficacious a solution of the neutral vanadiate of ammonia, 1 lb. in 10 gal. water. The operation should be conducted at a moderate heat, which is favourable to obtaining a fine black. This process is recommended in place of curriers' blacking for leathers of an open texture, as for shoes, harness, etc.
It is easy to produce reserves by applying the solution of vanadium only to some particular parts of the leather, leaving the rest untouched, la saddlery a very elegant effect is produced spontaneously owing to the circumstance that the waxed thread of the seams does not take the colour, but retains its own colour, and appears as a light design upon a black ground. The operator in this kind of leather dyeing does not soil his hands. There is produced a true, penetrating, and durable dye in place of a mere superficial coating, which often requires renewal and becomes lighter with time. (Teint. Prat)
(9) 4.2 oz. bruised gallnuts and 17.5 oz. green nutshells are boiled in 26.25 oz. rain-water. When the mixture has boiled 1 hour, the liquor is strained through a cloth. The leather to be coloured is first stained with the solution of iron filings, common salt, and vinegar, as given under purple, before the above decoction is applied.
2.2 lb. elderberries are boiled with 1.05 oz. alum, free from iron, in 2.2 lb. wine vinegar, and this solution is also filtered. If leather is to be coloured blue, the decoction of elderberries is applied uniformly with a sponge. When the coating is dry, it is brushed over lightly with solution of blue vitriol in vinegar.