Screen printing process esp. for maps or charts - uses 60-point pattern produced by electronic pick-up and printed with carbon free ink

摘要

The method for making a screen print consists of forming a 60-point coloured screen with a density of about 15%. A typical pattern has about 3600 points per square centimetre. The method is particularly suitable for maps or charts. The screen pattern is formed as a succession of lines forming an acute angle typically 45 deg. with the frame; an electronic pick-up device is used to form the points for printing and is used in conjunction with a printing ink which is free of carbon contamination. The screen may be formed as a stencil with infra-red rays being used for copying.