Popular Photographic Printing Processes; A Practical Guide to Printing with Gelatino-Chloride, Artigue, Platinotype, Carbon, Bromide, Collodio-Chlorid - Softcover
Synopsis
This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1898 edition. Excerpt: ...one; by passing the finger along the edge one can generally feel which way the paper tends to curl. Another test is to slightly moisten the first finger and thumb, with which grasp one corner of the paper, and hold tight for half a minute. The sensitised surface will stick to the finger or thumb to a much larger extent than the plain; this is due to the gelatine in the emulsion. The Alkaline Development of Bromide Paper.--As regards alkaline development there is this in its favour over and above what has already been said--that the permanency of the print is likely to be greater than where the acid iron developer and the subsequent acid clearing baths are employed; Abney and others have long pointed out the risk which ensues when a print containing acid, even in a minute proportion, is placed in a fixing-bath of hypo. Another point in favour of the alkaline developer is that the acid baths used, between the developing and the washing which precedes fixing, are dispensed with. The procedure necessary with development follows so normal a course, that but little special instruction is called for. Only this, that the constituents of the developers which follow may with much advantage be from time to time varied, in order to suit the circumstances of any particular print. Diluting the developer produces more delicate tones, with an inclination to want of vigour in the shadows. For over-exposure it is better to rely upon the bromide, or other restrainer employed, than upon dilution to slow down the rate of development. The first, and I am inclined to think the best developer of all is amidol. We are all so accustomed to keeping the ingredients of developers in solution, and mixing them up when ready dissolved, that some may have a fanciful...
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