Young's Demonstrative Translation of Scientific Secrets Part 29

Rule First.--Procure a frame one inch longer than the engraved part of the print. Second.--Cut the engraving the size of the frame, then make a stiff paste, and spread thickly on the frame. Third.--Place the engraving face down and sponge it gently with water; then press the frame firmly and evenly down on; leave it till entirely dry (not by the fire) and it will become even and tight.

To make the Grecian Varnish.--Take one part turpentine, two parts alcohol, (90 proof,) three parts balsam of fir, and mix.

To use the Varnish.--Pour sufficient spirits of turpentine on the back of the picture to moisten it well, then put on the varnish and rub it THOROUGHLY with a stiff brush, and continue to apply it until the picture is perfectly transparent.

Spots.--Leave the picture for twenty-four hours, after which if white spots appear, showing that the varnish has not been effectual, repeat the process. Sometimes it has to be done several times.

Drying.--Place the picture, face downward, where it will be free from dust, and leave it three or four days.

Paints.--These are put on the back of the engraving.

Eyes.--For blue eyes, permanent blue and white; for hazel eyes, yellow ochre and vand.y.k.e brown.

Flesh Tints.--Flake white, with a very little vermillion and Naples yellow.

Foliages.--Chrome yellow and Prussian blue, with any of the browns.

Sky.--Clouds touched in with white; the rest permanent blue and white.

Water.--The light parts with white, the rest the same as the sky.

If a bright scene, and with trees, of a greenish brown.

Hair and Eyebrows.--Yellow ochre and vand.y.k.e brown, or raw sienna.

Backgrounds.--The most agreeable tint is a greenish brown.

White Background.--Flake and silver white.

Buff Background.--Naples yellow.

Orange Background.--Chrome yellow, with vermillion.

Blue Background.--Flake white and Prussian blue.

Gray Background.--White, Prussian blue, and vermillion.

Pink Background.--White and vermillion.

Crimson Background.--Vermillion and white, with carmine.

Green Background.--Chrome yellow and Prussian blue.

Paints for the front of the picture.--Drying oil must be used with all the colours on the front.

Shading for the flesh on the front.--Carmine and vand.y.k.e brown laid on lightly, and the edges touched off with the finger.

Cheeks.--Carmine; soften the edges carefully.

Lips.--Carmine, with a touch of vermilion.

Hair and Eyebrows.--Yellow lake and vand.y.k.e brown.

Draperies.--These are always painted on the back, and shaded on the front with vand.y.k.e brown.

Backgrounds.--If plain, glaze with yellow lake.

Foliages.--Yellow lake and vand.y.k.e brown.

General Directions.--First.--Lay the paint thickly on the back, and be careful to cover every part, but not to go over the edges.

Second.--When the painting is finished let it dry four days, and then cover the front with a coat of mastic varnish.

Materials required are a palette, palette-knife, flat varnish brush, three sizes of bristle brushes, three sizes of table brushes, drying oil, mastic varnish, spirits of turpentine, Grecian varnish.

Colours used are oil colours in tubes. Those generally needed are silver white, Naples yellow, yellow ochre, brilliant yellow, vermilion, Prussian blue, raw sienna, ivory black, carmine, yellow lake, vand.y.k.e brown.

If economy is an object, some of the above-mentioned materials can be dispensed with.

550. DIAPHANIE

This is a beautiful, useful, and inexpensive art, easily acquired, and producing imitation of the richest and rarest stained gla.s.s; and also of making blinds, screens, skylights, Chinese lanterns, &c., in every variety of colour and design. In decorating his house, a gentleman spends as much money as he can conveniently spare; the elegancies and refinements of modern taste demand something more than mere comfort; yet though his walls are hung with pictures, his drawing-room filled with bijouterie, how is it that the windows of his hall, his library, his staircase, are neglected? The reason is obvious. The magnificent historical gla.s.s might be envied, but could not be brought within the compa.s.s of ordinary means. Recent improvements in printing in colours led the way to this beautiful invention, by which economy is combined with the most perfect results. A peculiar kind of paper is rendered perfectly transparent, upon which designs are printed in gla.s.s colours, (vitro de couleurs,) which will not change with the light. The paper is applied to the gla.s.s with a clear white varnish, and when dry, a preparation is finally applied, which increases the transparency, and adds tenfold brilliancy to the effect. There is another design, printed in imitation of the half-light (abatiour;) this is used princ.i.p.ally for a ground, covering the whole surface of the gla.s.s, within which (the necessary s.p.a.ces having been previously cut out before it is stuck on the gla.s.s,) are placed medallion centres of Watteau figures, perfectly transparent, which derive increased brilliancy from the semi-transparency of the surrounding country.

To ascertain the quant.i.ty of designs required, measure your gla.s.s carefully, and then calculate how many sheets it will take. The sheets are arranged so that they can be joined together continuously, or cut to any size or shape.

Practical Instructions.--Choose a fine day for the operation, as the gla.s.s should be perfectly dry and unaffected by the humidity of the atmosphere. Of course, if you have a choice, it is more convenient to work on your gla.s.s before it is fixed in the frame. If you are working on a piece of unattached gla.s.s, lay it on a flat table, (a marble slab is preferable,) over which you must previously lay a piece of baize of cloth to keep the gla.s.s steady. The gla.s.s being thus fixed, clean and polish the side on which you intend to operate, (in windows this is the inner side,) then with your brush lay on it very equably a good coat of the prepared varnish; let this dry for an hour, more or less, according to the dryness of the atmosphere and the thickness of the coat of varnish. Meantime cut and trim your designs carefully to fit the gla.s.s, (if it is one entire transparent sheet you will find it little trouble;) then lay them on a piece of paper, face downwards, and damp the back of them with a sponge, applied several times, to equalise the moisture.

After this operation, arrange your time so that your designs may now be finally left to dry for fifteen minutes before application to the gla.s.s, the varnish on which has now become tacky or sticky, and in a proper state to receive them. Apply the printed side next to the gla.s.s without pressure; endeavour to let your sheet fall perfectly level and smooth on your gla.s.s so that you may avoid leaving creases, which would be fatal. Take now your palette, lay it flat on the design, and press out all the air bubbles, commencing in the centre, and working them out from the sides; an ivory stick will be found useful in removing creases; you now leave this to dry, and after twenty-four hours apply a slight coat of the liqueur diaphane, leaving it another day, when if dry, apply a second coat of the same kind, which must be left several days: finally, apply a coat of varnish over all. If these directions are carefully followed, your gla.s.s will never be affected by time or by any variations in the weather: it will defy hail, rain, frost and dust, and can be washed the same as any ordinary stained gla.s.s, to which, in some respects, it is even superior. It is impossible to enumerate the variety of articles to the manufacture of which diaphanie may be successfully applied as it is not confined to gla.s.s, but can be done on silk, parchment, paper, linen, &c., after they have been made transparent, which may be accomplished in the following manner:-- stretch your paper, or whatever it may be, on a frame or drawing board, then apply two successive coats (a day between each,) of diaphanous liquor, and after leaving it to dry for several days, cover it with a thin layer of very clear size, and when dry it will be in a fit state to receive the coat of varnish and the designs.

Silk, linen, or other stuffs, should be more carefully stretched, and receive a thicker coat of size than paper or parchment; the latter may be strained on a drawing or any other smooth board, by damping the sheet, and after pasting the edges, stretching it down while damp. Silk, linen, or other stuffs require to be carefully stretched on a knitting or other suitable frame. Take great care to allow, whatever you use, time to dry before applying the liqueur diaphane. All kinds of screens, lamp-shades, and gla.s.ses, lanterns, &c., &c., may be made in this way, as heat will produce no effect upon them. The transparent pictures are successful, because they may be hung on a window frame or removed at will, and the window blinds are far superior to any thing of that kind that have yet been seen.

Instead of steeping the designs in the transparent liquor at the time of printing them, which was previously done in order to show their transparency to the purchaser, but which was practically objectionable, as the paper in that state was brittle, and devoid of pliancy, necessitating also the use of a peculiarly difficult vehicle to manage (varnish) in applying it to the gla.s.s, the manufacturer now prepares his paper differently, in order to allow the use of parchment size in sticking them on the gla.s.s. The liqueur diaphane, which is finally applied, renders them perfectly transparent. In this mode of operation, no delay is requisite, the designs being applied to the gla.s.s immediately after laying on the size, taking care to press out all the air bubbles, for which purpose a roller will be found indispensable. The designs should be damped before the size is applied to them. We are of opinion that this art may be applied to the production of magic-lantern slides, dissolving views, and dioramic effects; though we are not aware whether such experiments have been tried.

551. WATER-COLOURS USED IN DRAWING

Indian Ink.--The best is stamped with Chinese characters, breaks with a glossy fracture, and feels smooth when rubbed on the plate.

Hair Pencils are made of camel's-hair; if they come to a point, when moistened, without splitting, they are good.

Drawing Paper.--That made without any wire marks, and called wove paper, is the best; it is made of various sizes and thicknesses.

To make a good white.--Clarify white lead with white-wine vinegar.

After the powder has settled, pour off the vinegar, put the powder into a gla.s.s of water, stir it, and pour the water off while it is white into another gla.s.s; when it is settled, pour off the water, and an excellent white will be obtained. To this add gum enough to give it a gloss.

552. DIRECTIONS FOR MIXED COLOURS

Ash Colour.--Ceruse white, Keating's black and white, shaded with cherry-stone black.

Bay.--Lake and flake white, shaded with carmine; bistre and vermilion shaded with black.

Changeable Silk.--Red lead and masticot water, shaded with sap-green and verdigris.