The Optical Magic Lantern Journal (August 1891)

The Optical Magic Lantern Journal and Photographics Enlarger. 137. are expensive colours, and are not much used on this account. Flesh.—This is a perfectly transparent brownish red, sold in bottles by dealers in varnish colours. It is not a dye, but is of the nature of a varnish, and can be had either quick or slow drying. Gamboge.—A bright yellow, giving excellent greens when combined with Prussian blue. It has little intensity, and if prepared in oil is very slow in drying. Gamboge varnish can, however, be obtained, which will dry as quickly as mastic varnish. Italian Pink.—A bright yellow, more intense than gamboge, and therefore better for dabbing. Prepared in oil in the usual collapsible tubes, it is very slow in drying, many days being required, if not assisted by the application of heat. It is chiefly with weak colours, such as the yellows, that the advantage of varnish colours over oil paints becomes conspicuous. Yellow Lake.—This is similar to Italian pink, but it has a slight brown tinge. It is moderately intense, and pale tints can be dabbed with it ; it is rather slow | The yellows are all perfectly transparent, : in drying. but owing to the colour of artificial light being yellow or orange as compared with daylight, they usually appear very pale on the screen. Burnt Sienna.—A rich orange brown, fairly intense, and well adapted for dabbing; it also dries well. There are different qualities of this pigment in the market, some being more transparent than others; : but none are perfectly transparent, and hence the colour usually appears a little darker on the screen than on the slide. It is the most useful brown for the slide painter. Burnt Umber.—This is a darker brown than burnt sienna, and is intense, dabbing easily, and drying quickly. Itis not perfectly transparent, though there is little loss of richness in pale washes of the colour. is chiefly in the deeper tints that this defect shows itself. Asphaltum.—A perfectly transparent brown, not very intense. It is of the nature of a varnish, being made by dissolving asphaltum in oil or varnish. however, not so useful as the two preceding colours. Caledonian Brown Mummy and Vandyke Brown are other browns. yellowish tint : Caledonian brown is fairly transparent; and Vandyke brown is rich in colour, but loses considerably in richness when shown on the screen, It | It is, | Varnishes.—Oil colours require the addition of some suitable medium or varnish, in order to render them transparent. For slide painting, a good varnish should be free from colour ; when dry, the film should havea flat glassy surface, and be hard and tough, and not liable to soften much when heated. It should be of such a consistence that dabbing is possible, with or without the addition of colours; while it should also | dryin a moderate time ; and when dry, it should not soften if a subsequent layer of varnish is applied. | Such a varnish, made by careful mixture of several ingredients, can be obtained from the writer under the name of Special Varnish; it dries hard in fifteen minutes with the aid of heat. The varnishes obtainable at the artists’ dealers may also be employed, and a short description of their qualities may be useful. Mastic Varnish —This is one of the most colourless of varnishes, made by dissolving mastic gum in turpentine ; the gum dissolves very slowly. When applied to glass with the brush, it soon sets and becomes too hard for dabbing ; this may be cured by adding a little magilp. Mastic gum when heated becomes soft and almost liquid. : Copal Varnish.—This is not so colourless as mastic, but is cheaper, leaves a thicker film, and will do for comic slips and the like. Magilp.—This is a transparent, jelly-like substance, sold in collapsible tubes. and is said to be a mixture of mastic and drying oil. M-gilp dries very slowly ; but when it is dry it does not soften with heat, and is not liable to disturbance when subsequent work is applied. However, many days are required before magilp becomes thoroughly hard, but as with other varnishes, drying may be hastened by heat. : Canada Balsam.—A transparent cement, which may be thinned with turpentine, and used as a varnish. It is apt to leave a very sticky film, to which dust adheres, and it takes a long time to dry hard normally. When dry it will be found, on warming the glass, that the balsam becomes quite liquid again, hence its use requires judgment. Japanners' Gold Size.—This has a strong colour, and is unsuitable for blues and purples. brown For ‘other colours, however, it answers well ; it leaves a Mummy is quite transparent, of a | owing to want of transparency. Practically these three | colours can be dispensed with. Afauve.—This is a useful colour, as it gives us the : brightest violets procurable. The tint may be modified by adding other colours, such as blues and pinks. It is sold in collapsible tubes, also in bottles as a varnish colour. It is quite transparent, and __ sufficiently intense for dabbing, and is useful in skies and cast shadows. Verdigris is a rich green, fairly transparent, and very useful for grass, foliage, &c. The tint may be modified by the addition of yellow or burnt sienna. It ds not suitable for dabbing. Ivory Black, Lamp Black, Blue Black are all good intense pigments, capable of being dabbed, and of ; making excellent greys when diluted with varnish or megilp, and of producing sober tints when mixed with the bright colours. They dry quickly, especially when gnixed with mastic varnish. bright surface, dries quickly, and after a few days, the film does not soften again by heat. Linseed, nut, and poppy oils are not of much use in slide-painting, as they dry too slowly, and do not impart the transparence and smooth bright surface desirable. Magilp is perhaps the best substitute when an oily medium is wanted to mix with a quick-drying varnish. Brushes. —The “ brown water-colour sables ” are the best for colouring slides,either with varnish or with watere colours. The red sables are stiffer in the hairs. Two or three brushes will suffice ; one may be half-an-inch long in the visible portion of the hairs ; another may ‘be a size smaller; and one “liner” brush—the hairs about an inch long for painting fine lines—will be useful. The brushes should be fitted on sticks about four inches long ; an egg-cup containing turpentine will enable them to be readily cleaned after each tint is applied, the brush being first dipped in the fluid and then wiped on acloth. The brush should always be put away c!ean, with the hairs drawn toa point. If the hairs should become divergent and crooked, they may be corrected by dipping them in hot water and then stroking the hairs straight with the fingers.