A Study of Dot Shapes for Contact Screens.

Contact screens are described which produce a chain dot in the middletones of the reproduction rather than the conventional checkerboard-dot pattern. The new contact screens produce smoother middletones which are particularly advantageous when reproducing vignettes and smooth flesh tones; also, there is no enhancement of small defects, such as graininess, retouching marks, and flesh-tone blemishes. These results are illustrated with both black-and-white and color reproductions. The overall effect of the chain dot on tone reproduction is discussed and the methods used to measure the amount of chaining are described.