Process Control in Printing the Universal Product Code Symbol.

To reduce the amount of hand labor in supermarkets, the grocery industry has developed a Universal Product Code to be printed on package labels. This code will be read by a scanner at the checkstand and the cash register will be operated automatically. The package printer is called upon to print the code symbol according to specifications. The specifications require the determination of the variation in line spread for the given printing process This variation determines the size symbol required and the amount of compensation for line spread. The film master of the symbol must be measured precisely to assure that it meets dimensional tolerances. The accuracy and precision of the measuring system must be established and maintained by systematic control of the measurement process. The densities of the printed bars and spaces must be measured with an instrument designed for this purpose. The same instrument can be used to select colored inks for printing the symbol. Technical committees are considering a number of problems that have arisen in measuring symbols.