This section is from the book "Modern Photography In Theory And Practice", by By Henry G. Abbott. Also available from Amazon: Modern photography in theory and practice: A hand book for the amateur.
Each tissue added is to be three-eighths of an inch shorter than the one previously pasted in position. With a lead pencil number the tissue steps from 1 to 9. Cut up a piece of ordinary printing out paper into strips four inches long and a half inch wide. When the tissue strips are dried hard you are all ready for a trial of the actinometer. Place one of the sensitized slips with its face against the tissue paper, cover it with the wood strip and hold all in position by means of two small rubber bands, one at each end. We now select a negative, put it in the printing frame and place the carbon tissue over it, as in making ordinary prints. The printing frame and actinometer are placed side by side in a good bright light but not sunlight and examine the actinometer (by removing one of the rubber bands so you can see the printing paper) from time to time. The length of time which will be required to print, depends on the negative, as in other processes but when the sensitized strip under step six shows a decided color you will be safe to remove and develop your first print. If the development proves that your judgment was correct, then you will do well to mark the envelope belonging to this negative "Carbon 6" and you will know exactly what exposure it will require in the future for carbon printing. You can also make comparisons between this and other negatives and mark all those of a similar density and thus save much experimental printing. Carbon tissue prints in about the same time that the ordinary gelatine and collodion papers do. The next step is to develop your print and see if your exposure has been correct, for it would be folly to continue printing until you know you are right. There are two methods of making carbon prints, known respectively as the "single" and "double transfer process." We will first describe the development of the single transfer process, since it is the simpler of the two. To start with, we shall require four separate trays or dishes, some single transfer paper, a piece of glass or zinc, a print roller or squeegee and a good supply of hot water. A small glass thermometer will also be handy, especially to the novice. Of the dishes, three might be the ordinary trays used in development and for the fourth you should have an enameled iron dish. In the first tray put cold water, in the second hot water, 100° F., in the third cold water and in the fourth the fixing solution, which consists of one ounce of common alum to twenty ounces of water. Cut off a piece of single transfer paper a little larger than your print, put it in the first tray and allow it to soak for three or four minutes until it feels slippery to the touch. This transfer paper you purchase from the photo supply house at the same time you purchase the carbon tissue. You place the exposed carbon tissue also in this tray and you will note that it immediately begins to curl, the film side being in.
In a few minutes it will again begin to straighten out and just before it straightens bring it in contact with the single transfer paper under the water, the film side of the tissue being next to the slippery side of the transfer. Now slip under both of them the piece of glass or zinc spoken of, remove from the water and adjust the tissue until it is about central on the transfer paper. Hold it in position with the fingers on one end and pass the print roller over the tissue, pressing it firmly down into position. Now remove the fingers and press down the other half, working from the center. Now remove the zinc or glass from the back and substitute a few pieces of blotting paper. Place two or three pieces of blotting paper over the tissue and then put on a flat board and weight to hold the print flat and in position. At the end of a quarter of an hour we are ready to proceed. Of course it will be understood that if we were working a dozen or more prints, we could pile them on top of one another, with two or three sheets of blotting between each sheet and thus save time.
We are now ready for the development and we now fill the second dish with the hot water. In this dish we place the carbon tissue still adhering to the single transfer paper and turn the sheet over and over again as you would in toning. In a few moments you will note that the colored gelatine is beginning to run out from between the two sheets. About this time, take the print from the water and taking one corner of the tissue paper between the thumb and forefinger of the right hand, proceed to strip it from the colored gelatine. In some cases the tissue will stick and it must then be allowed to soak for a few minutes longer and it will generally come off without trouble. The remaining gelatine does not look very attractive, being a dirty mass of sticky matter but as we begin to bathe it with the hot water the superfluous gelatine melts and runs away, leaving the image behind it in the form of a pure black print. When the development has proceeded far enough, the print is transferred to the third dish containing the cold water, where it should remain for about five minutes and is then placed in the fourth dish, or hardening solution, where it should remain for fifteen or twenty minutes. After removing, it should be washed thoroughly in clean water and laid away or hung up to dry. To keep prints flat we advise laying them on a ferrotype plate to dry, film side up.
Now it may happen that the first print is either too dark or too light. If it is too dark, then we exposed it too long in the printing and if too light, then it is under exposed or printed. If we find that the print is not coming up as black as we should desire, being under printed, then place it in cooler water and it will sometimes save it and if over printed increase the temperature of the water. Under no circumstances should the film of the picture be handled until it is quite dry. On examination of the finished print you will see that it is reversed, i. e., those portions of the picture which were on the right in nature are now on the left and vice versa. Now in very many cases this will make no difference, particularly in landscapes but if the scene is a familiar one, or if it is a well-known public building, it would appear ridiculous and we should therefore have to employ what is known as the double transfer process in order to have the picture appear as the scene does in nature.
The manipulation for the double transfer process is similar to the single but the printed carbon tissue, instead of being squeegeed to a permanent support is first attached to what is known as a temporary support, then developed and again changed to its permanent support. The temporary support may consist of paper, metal or glass but in any event it must be coated with the following waxing compound, which can be purchased from the photo supply house or made at home:
Yellow Beeswax.......................................................25 grs.
Powdered Resin........................................................15 grs.
The beeswax should be cut into small pieces and placed in a bottle, the turpentine added and then dissolve by placing the bottle in a water bath. When the wax is all dissolved, add the resin and keep it in the bath until thoroughly dissolved. Take a small quantity of the compound on a clean linen rag and apply it to the surface of the temporary support and polish with a clean linen rag. The temporary support should be prepared before you start your printing. The final support, in the shape of paper, may be purchased from your photo supply house, or it may be glass, mica, wood or any substance that will stand washing in water. The final support should be soaked for about a quarter of an hour in a solution composed of
Powdered Alum....................................................... 4 drs.
The printed carbon tissue is soaked in water until soft and then transferred to the temporary support, which has previously been coated with the wax solution. This, of course, is done under water, as described in the single transfer process. It is now squeegeed, dried and developed, soaked in water and hardened as previously explained. After it is thoroughly washed it is brought into contact with the prepared surface of the final support and is then squegeed down firmly to it and allowed to dry. When thoroughly dry insert the end of your penknife under one corner of the temporary support and it will come away leaving the print in its final resting place. Where the final support is glass, polished metal or wood, there is a liability of the print not adhering well unless the surface is prepared for its reception. It is therefore well to coat the surface of the article. This coating is prepared by soaking 200 grains of gelatine in 16 ounces of water for three or four hours and then dissolving it in a water bath. Now dissolve 15 grains of chrome alum in four ounces of water and add it very gradually to the gelatine solution. Should the gelatine thicken too much add a few drops of acetic acid, shaking the bottle thoroughly. This should be applied in a thin coating to the wood or glass, which is to act as a final support and allowed to dry. The solution should always be applied warm. The final support should be soaked in water for a few minutes before the carbon print is applied. If the final print, after drying, be coated with this waxing compound mentioned for coating the temporary support, it will be waterproof and can be cleaned with a moist sponge or cloth when soiled.
There are occasions when the amateur would like to print a portrait, landscape, or marine upon a handkerchief, tidy or piece of satin or silk for a sofa pillow. This can be done readily by sensitizing the surface of the material and printing and developing the same in the ordinary way. Recently there has been placed upon the market an article known as "Sensitol" which the amateur will find very convenient for this purpose. It is a sensitizing fluid and gives a good photographic surface to any material that is sufficiently absorbent to retain a small quantity of it in its pores. The materials best adapted to this purpose are plain, unsized linen note paper, Whatman's hot pressed and other similar grades of waterproof drawing paper, postal cards and silk, satin, linen and cotton fabrics. Its manipulations are so simple that the merest beginner can get perfect results by following the directions.
The solution is to be applied to the surface with a camel's hair brush set in quill, or still better, set in hard rubber but never under any circumstance, with a brush set in metal, as the solution is decomposed by free metals. It can be applied by ordinary gas or lamp light, or by very weak daylight but the sensitized material must be dried and kept in the dark and in a place that is free from moisture.
Fabrics should be sensitized and printed on glass by laying the fabric over it. Full directions for preparing the work, printing and toning accompany each bottle.
A Meritorious Freak.