Dot Gain, What Is the Problem?

While densitometers remain the only convenient method of dot gain measurement for printing production control, research suggests that a wide variability can be created in the generation of the original or standard number for calibration. The original Print Planimeter was designed by PIRA in the UK. The current commercial Planimeter Beuvac Mark 111 measures geometric dot area by means of scanning a halftone image at any stage, from film positive, negative or bromide through plate to final print. A recent development for large format map measurement from film to print, cartography, takes the planimeter out of the laboratory and into the photomechanical area of production. Successful use of planimetry has been accomplished in UK and European newspaper production plants for the control of dot size in facsimile transmission of whole page data. Work is being done to further the combined, complementary use of planimeters and densitometers.