125. In the previous chapter we gave a brief summary of what the carbon process really is and what it accomplishes. In this chapter the practical working of carbon tissue will be described fully, without, however, any reasons being given as to the use of this or that chemical, or any explanations which might tend to confuse the beginner.

126. We will commence with the single transfer process, which reverses the image, but is simpler in operation than the double transfer method. The reversal is a minor point in pictorial work, but is, of course, useless for record work.

127. An impression which is quite prevalent among photographic workers, is that the process requires a liberal outlay for apparatus and materials with which to work, but there is really no doubt that it is based on a total misconception, as the outfit required is simple and inexpensive and some of the equipment necessary may be already in your possession. The following outfit is intended for prints 5x7 and under; larger prints will require larger trays, tissue, etc.:

128. Outfit Required

Outfit Required. There will be required one zinc or porcelain tray, 8x10, or larger, for sensitizing; two galvanized iron trays, 8x10, for developing; one ordinary tray-any size-for soaking the carbon supports; one rubber tray for alum fixing; one sheet of rubber cloth about 14 x 17 inches (not oil-cloth); one flat squeegee; one-half dozen wood photo clips; one actinometer; one large glass plate, on which to lay the tissue while squeegeeing out the surplus sensitizer; one broad rubber-bound camel's-hair brush; one thermometer; two dozen carbon tissues; six white matt celluloid supports; one package of assorted paper supports; twelve plain blotters, 5x8 inches; 6 ounces of bichromate of potash; one pound of powdered alum; one bottle of waxing solution; one bottle of collodion. Should smaller size tissues than the sizes included be desired in this outfit, they can be cut from the larger sheets to the size required. Half sheets are recommended for experimenting. For the final support with your first work, celluloid is also recommended, as this support can be used over again should you fail in the first attempt; while a paper support is ruined after once being used.

129. Carbon tissue is sold in rolls and in cut sheets of different colors. A package of cut pieces, of the size you purpose to work, should be purchased, the best color for the beginner being engraving black. The transfer paper first used should be smooth, providing celluloid is not employed. The squeegee required is a flat one, not a roller. It is well to get a fairly long one, as then it can be used for prints of any size.

130. Preparation

Preparation. The evening before making prints, proceed with preparations for sensitizing the tissue. This is quite a simple operation. (Formula No. 1.) One ounce potassium bichromate should be dissolved in 7 or 8 ounces of hot water, and then diluted to make 10 ounces. This is the stock solution and will keep in an ordinary corked bottle for any length of time without deterioration. For use, dilute one ounce of stock solution with water to make 5 ounces altogether. The diluted solution also keeps well, and there is no reason why the weaker solution should not be made up at once, if you have a bottle large enough to hold the 50 ounces of liquid, which will be the amount of the solution made up with one ounce of bichromate.

131. To keep down the list of necessary materials as much as possible, we have described a sensitizing bath consisting of a plain solution of potassium bichromate. Many experienced carbon workers use nothing else. Further on in this instruction are given formulae for other baths, but it is recommended that the beginner use the plain bichromate bath.