492 HANDBOOK OF PHOTOGRAPHY 



When local development is planned, it is best to use a gum-pigment mixture which 

 will give a slight staining with automatic development. To print slightly deeper than 

 normal, allow the development to go as far as it will automatically and do the brush- 

 work on the pigment stain. 



When development is complete, the print is hung up to dry. It will probably have 

 a slight amount of sensitizer stain, which may be removed by a few minutes' immersion 

 in a 5 per cent solution of potassium metabisulphite, followed by several rinsings in 

 clear water. Sodium bisidphite or ordinary alum may be used, but the potassium salt 

 seems to be rather more effective than either of these. It is commonly advised to use 

 alum, on the ground that it hardens the film, but the writer has not found this to be at 

 all necessary; the printed and developed film, after drying, is hard enough to stand 

 almost any amount of rough handling. Clearing should not take place until after the 

 print has been dried, or, in the case of a multiple print, until after the last printing 

 has been dried. 



Multiple Printing. — One reason that so many beginners in gum work get into 

 trouble is that they expect the first printing from the negative to look like a print and 

 try to make it do so. It should not; it shovdd look like a very sick imitation of a 

 print — pale, washed out, very likely no more than a flat tone in the shadows, and in 

 general thoroughly unsatisfactory. It is astonishing to an inexperienced worker to 

 see how the print assumes vigor and character with the addition of subsequent 

 printings. 



If the negative is soft enough so that its entire range of gradations is rendered in 

 one printing of gum, then when the print has been developed and dried it may be 

 coated a second time and printed again, for the same printing time, and developed as at 

 first. Thus the second and subsequent printings are used merely to add depth and 

 contrast. It is much more likely, however, that the scale of the negative will be too 

 great to render in one printing of gum, in which case the shadows^ — perhaps even the 

 half tones — of the first printing will be merely a flat tone and must be brought out by 

 the later printings. The coating mixture may, perhaps, be the same as for the first 

 printing but the printing time less, e.g., if the negative requires three printings to 

 render its full scale, the first one may be timed for 4 min., the second for two, and the 

 third for one, each printing being developed fully. Some workers have been known 

 to use 16 or 17 printings, and the writer knows of one who went to 25, but this is sheer 

 frivolity. Using a well-sized paper, which permits the use of a fairly large amount of 

 pigment, the utmost richness and depth of blacks can be got in five printings, and the 

 scale of practically anj^ negative can be rendered in six or eight printings. 



It will be apparent that very great variations in coating and printing are possible 

 in order to secure various effects. Thus a long scale may be secured with little depth 

 of shadow by using a relatively small amount of pigment in the coating mixture; or the 

 shadows may be emphasized by using light doses of pigment for the high-light and 

 half-tone printings, with a heavy amount, printed lightly, for the shadows. Each 

 worker will think up these variations for himself, but it cannot be too strongly urged 

 that he keep a record of what he has done in each case. If he fails to do this he will 

 not know where he is; he will be unable either to duplicate or to predict results, and 

 he is likely to abandon gum printing under the impression that it is too difficult. As a 

 matter of fact, gum printing is not at all difficult, but it does demand care and accu- 

 racy. Given these and a moderate amount of experience, gum printing will be found 

 not only much easier than bromoil or even than plain bromide enlarging, but far more 

 satisfactory in its results. 



General Remarks. — Registration in multiple gum has been the, subject of many 

 inventions; the simplest and best method is that recommended for multiple printing 

 in carbon, viz., the use of a mask around the negative, of a printing paper larger than 



