THE BRITISH JOURNAL OF PHOTOGRAPHY. November 1, 1860, p.314
[Read at the Meeting or the City of Glasgow and West of Scotland Photographic Society, October 4,1860.]
THE question is often asked by those who are about to supply themselves with photographic mementoes of the living: "Are they permanent?" I have no doubt as to the permanency if proper precautions be taken to free them from the chemicals used m the fixing. I am sorry that so many think a few hours' washing will do for the freeing of the print from the hyposulphite. It has always been my opinion that mere soaking is not sufficient if they are intended to be permanent. To my mind a certain amount of friction is requisite to force a union between the water, and the soda left in a newly-fixed print. Tepid water is an excellent substitute for pressure, as the soda dissolves much more rapidly in it than in cold water. I should not consider that prints floated in cold water would be at all permanent. It is the duty of all who are engaged in supplying the public with paper prints to do all in their power to make them permanent; if not, it will quickly tell upon themselves. The public will soon find out that they are not getting lasting mementoes, but "dissolving views."
I cannot say much about the old mode of toning and fixing, as I had little experience in it--I mean that of adding the gold to the soda, as recommended by Mr. Hardwich in his Photographic Chemistry. Till the introduction of a new mode. I thought most of the sel d'or toning bath. The principal difficulty was to prevent the, prints from running yellow. In other respects it gave very fine results. There was a richness of colour about them, and the half tones were well preserved. In consequence of the great care requisite in the washing when taken from the printing frame, and my not being able always to attend to that matter personally, I was obliged to give it up. I have some prints toned by that method five years since, and they are as good as ever. The paper at that time was not so good as it is now--at least I did not find it so.
I have brought with me to-night a number of other prints done by the method which I am about to describe. I have selected them with a view of showing you what a variety of tones can be produced by it. To look at them one would hardly think them done by the same process. By no means do I lay them before you as specimens of our art, but merely for reference during the discussion which is to follow the reading of this paper.
For the printing, good paper is essential.--There is much bad paper in the market--it remains with you therefore to try and get the best. . There is some good yet to be found. The plan I adopt is to try a number of samples till I get what I consider good, then secure as much as will keep, me for some time. Having got good paper, the next thing is to get good prints, which is not such an easy matter as the procuring of good paper.
First, cut the paper to the size that will suit you best, so as not to force you to have an unnecessary quantity of silver solution on hand. For cutting the paper you should have a bone knife, kept clean, for the purpose. Handle the paper as little as you can. It provokes one very much to see a dirty fellow "paw" the paper all over; and then; if there should be any stains in a finished print, he is sure. to blame the paper.
Secondly comes your silver bath.--Make it up to the strength of ninety grains to the ounce: of water, adding one drop glacial acetic acid to every ounce of the solution. At first thought some may think this a great waste of silver; but that is not the case, which may be proved by the following experiment:--Take ten ounces of a ninety-grain silver solution; pour it into a tray; then take the gross weight. Having previously cut twenty-four sheets of albumenised paper 8½ by 6½, take twelve of them, and float them just one minute each on the silver solution; preserve all the droppings; and add them to the tray. Now take the weight again, noting how much it has lost; then test for its strength: in this way you will find how much nitrate of silver you have lost. Next proceed in the same way, only take a sixty-grain solution, and float three minutes, which is the time generally allowed. I found, then, that it had cost me 10 per cent. more for nitrate of silver in the sixty-grain solution, and the prints were not so good. The first showed the image upon the surface of the paper, while the other looked as if seen through a veil. It is not enough that you should make the bath of the above strength, but that you should keep it up to it; testing it when you have ceased using it. Bear in mind, also, that albumen tends to neutralise the acid first added: but keep it always acid. By testing it with litmus paper you will soon discover, by the colour off the paper, when it; has enough. Pour now your silver solution into a flat dish, to about the depth of 3/8th of an inch. There is a danger in working with too little in the tray, as it is apt to cause bronze lines across the print: a halt when laying the paper has something of a similar effect. When you have the silver solution in the tray you will find a, dusty sort of scum all over it, which no amount of filtering will remove. The only way of getting rid of it is to take a slip of paper and pull it over, the surface, having its ends pressed close to the sides of the tray: letting down the paper: without thus cleaning the surface of the bath would cause the paper to have a marbled appearance on its surface.
All being now ready to lay the paper, take it in your hand by the end; let the other rest on the silver solution. Now lower it down as you would a plate on a flat (or horizontal) bath, having the light between you and the silver, so that you may see air bubbles. Let it lie only one minute; then raise it up at the end first down, so as to give it all the same time on the silver solution. Dry it in the dark room quickly by means of a stove, or as may suit you best. When dry, lay it in a drawer, so that it may absorb moisture again, and thus be brought to a uniform state. You will find it to lie better to the negative, and to give better tones in this damp state. It will be found a great advantage, if there is a lithographic press at hand, to give the sheets two or three pulls through: it will make the print much sharper, by giving the paper a finer surface. As to the keeping qualities of the paper just prepared, there is no fear of it for some time--I should say, for about a week--if you keep it from the light and in a dry place. I have brought a canister with me tonight; there is paper in it prepared two months back. If some one would take and print upon a piece of it, it would satisfy them as to what can be done in that way. I would not advise you to prepare it purposely; but if it so happened that you could not get your prepared paper printed, it might suit your purpose well. It would be a great advantage to the photographer-and more so in the winter months-if he could keep the paper till the light would suit. I have never been successful in the keeping of paper that has been floated upon the silver for three minutes.
Having followed these instructions, and thus got your sensitised paper, you must look to your:negative. If it is thin you had better turn it into the shade, as it will not print so well in sunshine, which has too powerful an effect upon the intense parts of your negative, causing the face to look flat and grey; but if, on -the other hand, the negative is strong or dense, the best effect ,will be got in sunshine. In fact, to print with taste, you should have two kinds of paper prepared--one as rich in silver as possible, and another a slightly salted and silvered kind-using the strongly silvered kind for the thin negative, and vice versa. I had almost said it; was a shame, but it is. a pity, that those who albumenise paper do not mark how much chloride it contains: till they do so, or we prepare it ourselves (which by the way is no great trouble), we must. be in a state of uncertainty as to what we are doing.
There is some attention required to see that all the parts are printing equally. You will find in some negatives parts which come out too rapidly: others-as in the case of groups, some being in the foreground--get overdone, so as to make the impression on the paper destitute of light or shade. There should always exist a certain amount of difference between those in the foreground and those in the back, but not to the extent that at times is produced in the negative; of course, without that the picture will be flat and worthless. There is, as the Yankee would say who has been writing to one of the Journals lately, a "little dodge which you may here practise." Take a large magnifying glass and hold it up to the sun, letting the focus (not the burning point) full on the face or faces, as the case may be. You can make the light large or small as you find it answer your purpose. The lens I use is about 10:inches diameter; and I have found it of great service to me when there was any thing white in the picture--such as a white dress, book, or letter--the details being visible when looking through the negative, but which would not print till all the rest of the picture was over-done. I don't lay down the use of the lens in this way as anything new: one cannot mention a thing that some one has not known before. I fear some of you may think I speak long about trifles. Your print is now ready for taking out of the printing-frame. In appearance it should be what you would say "just too dark." Some paper gives way much in the after toning and fixing; others little or nothing: practice can be your only guide. If you can be ready for toning in an hour or two, lay the print down on water (face downward) for about five minutes. This water should be kept till you have floated a number of prints on it; then throw it into a large jar kept for waste silver solutions. In the jar you may have some pieces of copper, which will reduce the nitrate to the metallic state. When you have a stock of it you may wash it and dissolve it in nitric acid; it will be quite good for the paper silver bath. Upon no account should the prints be immersed in the first washing water, as it would cause liability to stains, there being so much difficulty in removing the free nitrate out of the paper, and it throws down a quantity of the gold in the toning solution. After floating the proof on the first water, lift it up and plunge it into water kept constantly changing: a self-acting tray you will find a great advantage. Having turned them about three or four times in the hour or two they lie in the water, they are ready for toning.
Arrange now all your trays, side by side:--first your toning tray set inside another, so that you may pour warm water about the toning tray at pleasure; secondly, a tray with clean water; thirdly, the tray with the fixing solution. Toning solution:--chloride of gold in solution (one grain to the drachm of water) one drachm; water about two ounces; then drop in a piece of litmus paper, which at first will be reddened; then take a saturated solution of carbonate of soda, and add till the litmus is brought back to its blue colour--any more has a tendency to soften the prints. Throw it then into your toning tray. This is by far the best toning bath, as it combines simplicity with certainty. The fixing bath is as follows:--hypo. of soda 6 oz.; water 20 oz. Pour in as much as will cover the prints you have to tone--more is not required. Do not use the fixing bath twice, as there is no certainty of getting well-fixed prints after it has been once used. I have often found them turn yellow: if not at the time after a day or two. It is so pleasant to see pure whites, one should not grumble to spend a few pence in securing them.
In toning the print lift it out of the water, and pop it into the toning-tray: keep it in constant motion with your left hand. When it is rather darker than you would like it to remain, lift it out with the left hand; give it a rinse through the water with the right hand, then through the fixing-bath, letting it lie for fifteen minutes, with occasional turning, so as to insure its being well fixed. If air bubbles get between the print and soda they will cause spots from imperfect fixing. Some may wonder how I say, take the left hand for toning and the right for fixing. Were you to knock the hand into the gold solution that had been in the hyposulphite of soda it would deposit all your gold. I believe that through this very small matter the manufacturer is blamed when the bath will not tone more than two or three prints when it should have toned six at least.
I now go on with the toning of the other prints, working with the solution first made, till it becomes rather slow; when by pouring hot water about it, it starts off again; and so on till the last of the gold is wrought up. The prints having been left in the hyposulphite of soda for fifteen minutes, put them into water kept constantly changed (as before stated in a self-acting tray). Having allowed them to have two or three changes of cold water, then turn on the hot-say about blood heat: keep them constantly moving about for twenty minutes or so. You may now turn off the hot and let in the cold water for an hour or two; then allow them to soak all night, when you may turn on the water for an hour or two again. Some recommend that the prints should be dried off between folds of blotting-paper: that I think unnecessary. Hang them then over a line to dry; when dry they are ready for mounting.
Though the mounting of the prints does not exactly come under this head, yet I may be allowed to say a few words on so important a subject. After the prints are dry the first thing is to cover them over with patent starch paste: they are then dried, trimmed on the edges, and are ready for mounting on cardboard. Having a lithographic press all ready, take a wet sponge; and cover all over the cardboard. Lay the print you are to mount on the cardboard in its right place, holding the two together till you lay them face downwards on the stone: now put down the tympan, and one pull through will make them adhere, so that no amount of labour can take them off. In this way I can mount and press about 100 (8½ by 6½,) prints in one hour. There is another advantage in this mode--the boards do not turn up so much.