The paper gives the best results when not absolutely dry, but when very nearly so. It will be in the very best condition after it has been between the drying boards for perhaps half an hour or an hour.
If before use the drying boards be dipped in a satu rated solution of carbonate of soda (washing soda) and be then dried, the paper lying between them will keep white for at least a week.
For paper to become surface dry requires only a few minutes if the draining have been properly performed and if the room be dry. If the paper become quite dry it curls up in a way which at times makes it very diffi cult to get it flat enough to lay it in the frame. It may in this case be straightened in the following manner : A pad of blotting-paper and a blunt paper-knife are re quired. The print is laid out as nearly flat on the blotting-paper as it can be by hand, the back being upwards. The paper-knife is now drawn across the back, considerable pressure being given by the edge. After this has been clone for some time the paper will retain its flatness.
A 7 n112011ia Fuming of Paper.
When paper is sensitised as it is required it is com mon to fume it with ammonia. If such be clone the paper will print somewhat more quickly than when un fumed, and, at least with some operators, gives a more brilliant print.
Boxes or chests are made specially for fuming paper. The operation consists simply in exposing the paper to fumes of liquor ammonia. The boxes are pieces of apparatus wherein the paper is laid on string nettings, or is otherwise supported whilst it is acted upon by a mixture of one part of ammonia and three or four of water, which is placed in a dish under it.
The amateur who wishes to fume his paper on a small scale will easily think of means whereby such may be clone. For example, in an ordinary cupboard or ward robe a dish of ammonia may be placed whilst over it the paper flattened out, as already described, hangs on American clips. The usual time of fuming is a quarter of an hour or twenty minutes.
The operations of printing, toning, fixing, and wash ing of prints are almost precisely similar for the paper sensitised as we have described as for paper purchased ready sensitised.
It will probably be found, and especially in the case of fumed paper, that the print fresh from the frame has none of the brown colour which the print on ready sensi tised paper had, but appears as if it were already toned. Sometimes this colour will go off in the washing, giving place to the brick-red colour which we have already mentioned. If it will not, the desired change may be brought about by clipping the prints in water into which a little salt has been put. The precise amount of salt does not signify. The water should be made to taste slightly briny. The prints are dipped in this salt water, after they have been washed, till they are fairly free from silver nitrate. They are left in it for a few minutes, and are again washed for a like period.
It might be supposed that if a print appear when it comes from the frame to have the same colour as a toned print there can be no need to tone at all. This is by no means the case, however. The fixing-bath would soon remove the apparent tone, reducing the print to a very disagreeable yellowish-red shade.
Paper sensitised as required, and not fumed, takes somewhat longer to print than ready sensitised paper. That which is fumed takes about the same length of time to gain the same amount of darkness in the frame, but as it loses somewhat more in toning and fixing than ready sensitised paper does, it is necessary to print a little longer.
Before concluding our remarks on printing we must say a few words on the different effects produced by printing in a weak or a strong light. If a print he taken from a negative of average density in the fullest mid summer sunshine, and if another be taken in light so dull that it will require say a dozen times as long to print, the two will on comparison show a marked differ ence. The print taken in bright sunshine will show less contrast than the other. From this it follows that if we have a negative which gives a print slightly hard, but not so hard that we incline to apply a reducer, our best course is to print in bright sunshine. If, on the other hand, the print got is a Nile too soft we should print in a very weak light.