PRINTING PROCESSES 



417 



glossy prints both have longer scales of gradation than the matte by a factor of about 

 17 per cent. 



With a vigorous long-scale negative there will be more detail in the shadows of a 

 glossy print or a waxed surface than in those of a matte surface. This is true in spite 

 of the greater contrast. If the differentiation of tone of the matte print is satisfactory, 

 a negative must be less contrasty to give equal differentiation of tones on a waxed 

 surface or a glossy paper. In addition the glossy print will reproduce greater subject 

 brilliance because of the greater maximum black that can be attained in the glossy 

 print. 



At its maximum density the paper reflects about 1 per cent of the incident 

 light, which corresponds to a reflection density of 2. Therefore the longest tone 

 range possible is about 100 to 1. 



Varieties of Printing Papers Available. — Beside varying in contrast, printing papers 

 are made with various surface textures (smooth or matte, rough, glossjs canvas, etc.), 

 on paper backing material of various tints or colors, of various weights (single or double 

 weight, etc.) etc. These matters are treated more fully in the chapter on Photographic 

 Materials. 



B/ac/c 



Wh/Ye 



-. Tones in 

 \shaolows lost 

 j in final pri nf 



Black 



\ Tone range 

 I affinal 

 \ prinf 

 i 40fol 



Tonerange 

 ofprinr 



Tones in 

 / Opacify J ^. Ir'gh-lighfs 

 range of^ ' '°^''- >" P""'"^ 

 neaafive 

 I 'Opacify/ range of =50fo/ 



negafi ve =50 io] 

 Fig. 3. — Loss of shadow or high-light tones caused by using paper with too short an exposure 



range for the negative. 



Practical Considerations in Printing. Selection of Paper. — The printing paper 

 must be selected, not only with regard to the contrast to fit the negative to be printed, 

 or to produce the desired end result, but also with regard to the texture of the paper, 

 its thickness, and its color. These are matters of opinion rather than matters of 

 fact. 



Brightness Range Encountered in Practice. — Fortunately the brightness range of the 

 average outdoor or studio scene is such that ordinary negative materials will record it 

 accurately. Mees^ shows a photograph of a typical outdoor scene in which the bright- 

 ness of a sunlit cloud was 4250 ft.-lamberts and the deepest shadow had a brightness of 

 162 ft.-lamberts. This represents a brightness range of 26 to 1. Scenes with bright- 

 ness ranges of 100 to 1 do not reproduce well, nor do scenes of range of less than 10 

 reproduce well. It is seldom that brightness ranges greater than 20 or 30 to 1 will be 

 encountered. 



Most negative emulsions are capable of reproducing easily the ranges of brightness 

 found in studio or outdoor subjects. 



Effect of Using Improper Contrast Grade. — Suppose a subject has a brightness range 

 of 50 to 1 and that it is printed on a paper with an exposure range of 40 to 1. The 

 paper cannot reproduce the entire range of the subject. Suppose the paper is exposed 

 to the negative (which has an opacity range of 50 to 1) in such manner that the high 



1 Mees, C. E. K., "Photography," Macmillan (1937). 



