PRINTING PROCESSES 427 



itiiniature negatives. Every scratch, fingerprint, and speck of dust or lint is magnified 

 with the image, and an invisible flaw becomes a ruinous blotch when magnified 20 X . 

 It is practically impossible to retouch miniature negatives; all handwork must be done 

 on the final print. 



One of the virtues of projection printing is the ability of the photographer to select 

 a portion of a negative and to enlarge it to the desired degree. Often a negative 

 looked at in toto will not reveal an excellent composition which becomes evident when 

 only a portion is masked off and studied. 



To sum up, for the utmost in detail and freedom from grain, make contact prints. 

 For depth of focus, when the exposure must be short, for large prints, for dodging one 

 portion of the negative at the expense of another, for reproducing only a portion of a 

 negative, for soft effects, enlarge. 



Contact-printing Equipment. — Gaslight or chloride paper used for conta-ct printing 

 may be processed safely in a room illuminated by ordinary incandescent lamps, pro- 

 vided a safe distance is maintained between lamp and paper. A better method is to 

 use a yellow safe light to which the chloride paper is insensitive. The illumination 

 on the printing table may be fairly high so long as it is of a color which will not fog the 

 paper. 



For the amateur a printing box is useful. This is simply a box with one or more 

 bulbs (of 40 or 60 watts each) in it together with a small ruby lamp. A switch is 

 connected with a hinged cover so that, when the exposure is to be made and the cover 

 is pressed down, the exposing lamp is turned on and the ruby lamp is turned off. 

 Between the exposing lamps and the negative is a diffusing ground glass. Some sort 

 of reflector in the box aids in securing even illumination. 



Printers for professional use are of the same general type but are more complex and 

 are capable of accommodating larger negatives. 



Making Contact Prints. — Contact printing involves these several steps: 



1. Placing negative in printing machine or frame, emidsion side up. 



2. Placing printing paper in contact with the negative, emulsion side down (the two 

 emulsion surfaces are now in contact). 



3. Turning on printing light, or if a printing frame and an external light source are 

 used, bringing the frame near the exposing light. 



4. Developing, rinsing, fixing, washing, drying, and mounting. 



With a printing box or machine it is difficult to "dodge," i.e., to expose one portion 

 of the negative more or less than another part for the purpose of improving contrast of 

 a particular portion or to even up the final brightness over the entire print. If a 

 printing frame is used and the exposing light is fixed at a conA^enient distance from the 

 frame, a piece of cardboard or other opaque material may be interposed between the 

 light and the portion of the negative which is to be held back. 



If a printing frame and an external source of light are used, it is wise to move the 

 frame with respect to the lamp so that even exposure over the entire picture is secured. 

 A simple light box can be made, however, which may consist of several incandescent 

 bulbs of small size (perhaps, 25 watts) placed in the bottom. Between these lamps 

 and the printing frame is a sheet of diffusing glass or paper. 



A normal contact paper placed about 1 ft. from a 60-watt lamp will require 10 to 

 20 sec. exposure when printed from an average negative. It is wise to make a test of 

 the exposure by using a small strip of the paper before exposing the entire sheet. This 

 test strip is placed over a portion of the negative which has both high lights and shad- 

 ows. The exposure should be such that after development the high lights show a 

 just perceptible coloring compared to a sheet of unexposed paper. 



It is good practice to arrange the printing light and the printing frame in such a 

 manner that exposures of the order of 4 or 5 sec, minimum, are required. At one time 



