Density Measurement - Printing Color Measurement Standard

In the offset printing process, the thickness of the ink on the paper changes with the increase of ink flow in the ink fountain. The ink density, the process control, was set on the press and was previously observed with the eye. But over the past decade, color measurements have been made using density measurements. Standards developed using densitometer measurements are SWOP, SNAP, and GRACoL.

Quality control includes the following features:

1. Monitor the process control of the press, monitor the consistency of the print, and track the production variables. Printing operators are most concerned about printing density and dot gain, and further analysis is based on ink overprint conditions, print contrast, color difference, and gray balance.

2. Measurable production variables affecting image quality, including: the film dot area of â€‹â€‹the photo-composing machine, the size of the print dot of the printing plate or the CTP plate. To measure these variables, the QC department has a densitometer or spectrophotometer for the printing plant.

Because of the low contrast of the image and non-image parts, using a densitometer to read data from a CTP or a conventional plate has measurement problems. BetaScreen and Tobias claim that they have optical densitometers that can accurately read the data on the plates.