Part 6 (1/2)

Inches. Lbs.

Emperor, 72 48 620 Antiquarian, 53 31 250 Double Elephant, 40 26-3/4 136 Atlas, 34 26 98 Columbier, 34-1/2 23-1/2 102 Imperial, 30 22 72 Elephant, 28 23 72 Super Royal, 27 19 54 Royal, 24 19 44 Medium, 22 17-1/2 34 Demy, 20 15-1/2 25 Large Post, 20-3/4 16-3/4 23 Post, 19 15-1/4 20 Foolscap, 17 13-1/2 15 Pott, 15 12-1/2 10 Copy, 20 16 20

TO MAKE BRONZED PAPER.

Dissolve gum lac in four parts by volume of pure alcohol, and then add bronze or other metal powder in the proportion of one part to every three of the solution. A smooth paper must be chosen, and the mixture applied with a fine brush. The coating is not dull, and may be highly burnished.

Another process consists in first applying a coat of copal or other varnish, and when this has become of a tacky dryness, dusting bronze powder over it. After remaining a few hours, this bronzed surface should be burnished with an agate or steel burnisher.

TO MAKE DRAWING-PAPER TRANSPARENT.

Drawing paper of any thickness may be made perfectly transparent by damping it with benzine. India ink and water colors can be used on this paper. The paper resumes its opacity as the benzine evaporates, so that any place that has not been duly traced requires to be redamped with the benzine for that purpose. A sponge should be used for the application.

TO MAKE PAPER WATER-PROOF.

The following is a recipe for making paper water-proof:--Add a little acetic acid to a weak solution of carpenters' glue. Dissolve also a small quant.i.ty of b.i.+.c.hromate of potash in distilled water, and mix both solutions together. The sheets of paper are drawn separately through the solution, and hung up to dry.

HOW TO SIZE POOR DRAWING PAPER.

To size poor drawing paper, take one oz. of white glue, one oz. of white soap, and one-half oz. of alum. Soak the glue and soap in water until they appear like jelly, then simmer in one quart of water until the whole is melted. Add the alum, simmer again and filter. To be applied hot.

TO PREVENT ALTERATIONS IN WRITING.

The following process of preparing paper will prevent alterations in writing:--Add to the sizing 5 per cent of cyanide of pota.s.sium and sulphide of antimony, and run the sized paper through a thin solution of sulphate of manganese or copper. Any writing on this paper with ink made from nutgalls and sulphate of iron, can neither be removed with acids nor erased mechanically. Any acid will change immediately the writing from black to blue or red. Any alkali will change the paper to brown. Any erasure will remove the layer of color, and the white ground of the paper will be exposed, since the color of the paper is only fixed to the outside of the paper without penetrating it.

TO PREVENT GUMMED PAPER FROM c.o.c.kLING.

It is well known that paper, when gummed, often c.o.c.kles. To remedy this a little glycerine or sugar should be added to the gum.

COPYING DRAWING IN COLOR.

The paper on which the copy is to appear is first dipped in a bath consisting of thirty parts of white soap, thirty parts of alum, forty parts of English glue, ten parts of alb.u.men, two parts of glacial acetic acid, ten parts of alcohol of 60, and 500 parts of water. It is afterwards put into a second bath, which contains fifty parts of burnt umber ground in alcohol, twenty parts of lampblack, ten parts of English glue, and ten parts of b.i.+.c.hromate of potash in 500 parts of water. They are now sensitive to light, and must, therefore, be preserved in the dark.

In preparing paper to make the positive print, another bath is made just like the first one, except that lampblack is subst.i.tuted for the burnt umber. To obtain colored positives the black is replaced by some red, blue, or other pigment.

In making the copy, the drawing to be copied is put in a photographic printing frame, and the negative paper laid on it, and then exposed in the usual manner. In clear weather an illumination of two minutes will suffice. After the exposure the negative is put in water to develop it, and the drawing will appear in white on a dark ground; in other words, it is a negative or reversed picture. The paper is then dried and a positive made from it by placing it on the gla.s.s of a printing frame, and laying the positive paper upon it, and exposing as before. After placing the frame in the sun for two minutes, the positive is taken out and put in water. The black dissolves off without the necessity of moving back and forth.

WAs.h.i.+NG FORMS.

Forms sent down to machine ought not to be wet too much with lye or with water, otherwise it becomes necessary to dry them before working, which takes time and often much trouble. The wet works up little by little to the face of the letter, and then the form becomes unworkable. It has often to be taken off the coffin, the feet of the types have to be thoroughly dried, then some sheets of unsized paper have to be placed under the form; it has also to be unlocked, shaken, locked up again, the sheets removed with the moisture they have imbibed, and then it is to be hoped the form will be workable. If not there is nothing to be done but to lift it and dry it by heat.

Lye is generally used for was.h.i.+ng forms which do not contain wood blocks; turpentine where wood-cuts or wood-letters are to be found in them. The bristles of the lye-brush should be longer than those of the turpentine-brush, and, in order to preserve it, each brush should be properly washed with water after using, and shaken and stood up to dry. If this is not done the brush will last but a short time.