HALFTONE SCREEN — KAINEN 417 



ner's English patent otherwise had very little originality, and the 

 screens he suggested using were to be of wire, gauze, insect wings, 

 or other textural materials, but since it did make suggestions for dif- 

 fusing light, however tentatively, it is worthy of note. Faulkner 

 suggested shading portions of the object during exposure, or (lu-ow- 

 ing it (the object) "a little out of focus by inclining it more or less 

 to the plane of the picture, or a lens may be employed which focuses 

 part but not the whole of the object." Faulkner was concerned with 

 obtaining a greater range of gradation in halftone, striving to create 

 the effect of distance, transparency, and opacity as in nature, and it 

 is this preoccupation that gives meaning to his otherwise fruitless 

 efforts. 



With the 1879 patent of Sir Joseph Wilson Swan came the first 

 glimmerings of the modern idea of spreading light through a screen 

 for better gradation. Swan stated, "The screen is moved periodically 

 so that a stronger impression of the lines and a greater number of 

 crossings are obtained in the shaded portion, or vice versa if a positive 

 transparency is used." This idea marked something of a turn in the 

 road, for, although Berchtold had spoken of turning the screen in 

 his 1857 patent, his intention had obviously been to create a cross- 

 grain of lines of equal thickness rather than diffuse the light to obtain 

 lines of unequal thickness. While at first glance Swan's idea is almost 

 identical with that of Berchtold, the fact that certain lines were to be 

 stronger than others implies a diffusion of light to obtain heavier or 

 lighter images of the lines on the sensitized plate. These plates, ac- 

 cording to Swan, could be used for the swelled-gelatin process or for 

 "photo-etching purposes," or, in other w^ords, for etched halftone 

 relief printing. 



In 1881 Frederick E. Ives of Philadelphia patented the first really 

 successful commercial method for creating letterpress halftones. 

 His method, however, conceived in 1878, was slow and indirect, and 

 it did not make use of a screen; nevertheless, it did break up the 

 j^hotographic image into numerous dots of varying size. The Ives 

 process was based upon a swelled-gelatin relief that was used to make 

 a hollowed plaster cast. A glass plate having a surface composed 

 of elastic pyramidical projections was then inked and pressed against 

 the wdiite plaster. Where the swelled-gelatin impression had left 

 the plaster deepest, the tips of the pyramids scarcely touched, and 

 so created fine dots; and, at the other extreme, where the plaster 

 was highest the pyramids would squeeze flat, creating heavy dots. 

 Intermediate portions would receive dots proportionate in size to 

 the varying levels of the plaster. The plaster cast was then photo- 

 graphed and reproduced as line copy. It has been said that Charles 

 Petit of Paris patented a similar process in 1879. This is not quite 



