SPECIAL PRINTING PROCESSES 499 



ing and inking for more than a week or so, since with time the gelatin tends to become 

 hard and resistant to swelling. 



Printing for Bromoil. — Printing may be either by contact or by enlarging, though, if 

 the former is used, there is no gain over oil and there is the additional — and sometimes 

 tricky — operation of bleaching. To be satisfactory for bromoil, the enlargement 

 should be distinctlj^ on the soft side; there should be no very deep shadows, since if 

 these are present it will be difficult to hold up shadow detail in inking; and the lights 

 should be a trifle darker than thej^ would be for the ideal bromide print. If this 

 quality is maintained, inking will be much easier than otherwise, and, though it is 

 desirable to adjust the negative so that the ideal print quality is maintained with 

 normal treatment, this is not absolutely imperative. If the negative is slightly too 

 strong, a satisfactorily soft bromide print may often be secured by giving two or three 

 times normal exposure, diluting the developer to about a quarter of normal strength, 

 and removing the print from the developer when the lights have reached the proper 

 depth. This technique is a "touch-and-go" sort of performance, since the tray must 

 be rocked constantly if uneven development is to be avoided. The print must be 

 snatched at exactly the right point — a trifle before it reaches the desired depth — and it 

 must be promptly and evenly immersed in the hypo, where it is rocked for ^i min. or 

 so after immersion. Still, this plan is often useful, especially since it is not at all 

 necessary, with bromoil, that the print be developed to infinity, as is required when 

 toning by the bleaching and sulphiding process is contemplated. 



Almost any developer which is suitable for bromide paper can be used, though it is 

 generally best to employ Amidol, since this, working without alkali, has little or no 

 chemical effect on the gelatin. 



Many bromoil workers favor a stop bath between development and fixing, giving 

 the print }/2 niin. or so in 



Water 1000 . cc. 32 oz. 



Acetic acid (28 per cent) 45.0 cc. 1>2 oz. 



or (which is the same thing) 



Water 1000.0 cc. 32 oz. 



Acetic acid (glacial) 12 . cc. 3 drams 



The present writer, however, prefers to put the print directly from the developer 

 into the hypo, a technique which demands clean trays, clean hands, and prompt work- 

 ing if stains and uneven development are to be avoided, but which, in his opinion, gives 

 a print which is more easily inked than if the intermediate acid bath is used. 



Fixing must be done in a 25 per cent solution of plain hypo, since any hardening 

 of the gelatin must be avoided. Washing after fixing must be thorough, since if any 

 trace of hypo remains in the emulsion it may react with the chemicals of the bleacher, 

 causing uneven tanning of the gelatin. 



Bleaching. — Bleaching may take place immediately after washing, or the print 

 may be dried and then bleached at some future time. It is not well to postpone the 

 bleaching too long, or the gelatin may tend to harden spontaneously. If a dried print 

 is to be bleached, it should first be soaked in water until thoroughly limp. 



It is not possible to give a general formula for the bleacher, since this varies with 

 different papers, with different inks, with the temperature of the soaking water, with 

 the worker's stj^le, and with the results desired. Each bromoil worker, therefore, must 

 try different techniques until he finds that which is most satisfactory. 



A technique of bleaching which is recommended by John Kiem, of the Orange 

 Camera Club, for Defender Velour Black, is as follows: 



