TONING AND FIXING OF PRINTS.
Various toning - baths are used by different photo graphers, each one as a rule considering that he finds some special virtues in the bath which he uses. We will give several baths, all of which we have found to work excellently with both ready sensitised paper and paper prepared as required. We will give first that known as the borax bath.
The tube of chloride of gold which contains fifteen grains is dropped into a pint bottle. A glass rod is taken and the tube is broken with it. Fifteen ounces of water are now poured over the chloride of gold, and the bottle is labelled " Chloride of gold solution ; one grain to the ounce." When we are about to tone we count our prints and calculate how many sheets of paper there are, or how great a fraction of one sheet if we have been printing only a few small proofs. This is for the sake of finding how much toning solution we ought to mix up. For each sheet of paper measuring 17 x 22 inches we take ninety grains of borax, which should be in the form of a powder. On this we pour a few ounces of hot water to dissolve the salt. We now make up with cold water to fifteen ounces, and add one ounce of the stock solution of chloride of gold.
This forms our toning-bath. It must be mixed within an hour or so of the time when it is to be used, as it does not keep well. Care must, moreover, be taken not to add the gold while the borax solution is still very warm, or the gold may be thrown down.
All the processes in connection with toning and fixing of prints must be performed in a light not strong enough to act upon them. The best arrangement of all is to have a yellow light for all processes except that of toning, for which white light is necessary to enable judgment of the colour to be made. It is quite possible, however, to perform all the processes in a white light so feeble that no hurt will come from its use.
The first operation is to wash the prints. If a special piece of washing apparatus is not used this is best done in the following manlier : One of the flat dishes is laid on the operating table filled with water, and the prints are laid one by one face downwards in this. When all
have been so laid in the dish the water is poured off. More water is poured into the dish over the prints, and a second dish is placed, full of water, alongside the first. The prints are lifted one by one from the first to the second dish till all are in the latter, when the water is once more drained away. Clean water is again poured into both dishes, and the transference from the second to the first is commenced.
It will be noticed that the water which is poured from the prints is no longer clear, but has a milky appearance. This is because some of the silver nitrate—which it is the object to wash away—combines with salts, which are always present in tap water to a greater or less extent, and produces a precipitate. This is a very con venient test for the amount of washing which is necessary. As long as the water which drains from the prints appears when placed in a tumbler or glass measure to be in the least cloudy, the washing process has to be continued. When there is no more cloudiness we may commence toning.
The three dishes are arranged in a row along the front of the operating table. In the first or left-hand dish there are the prints which are about to be toned, the dish being kept full of clean water. In the second or middle dish is poured the toning solution. In the third or right hand dish goes clean water, into which some like to place a little common salt, so as to quickly arrest the toning process when the prints are placed in it. If salt is used it does not matter very much what quantity is taken, but there should be enough to make the water taste briny.
It will have been noticed that, whilst the washing was going on, the prints turned from the brown colour which they had in the frames to something very nearly approaching brick-red.