Why are eyespots and color bands printed on some polybags?

Dec 2016

Both eyespots and color bands are printed onto the bags to assist in the printing and converting processes to ensure a higher quality end product. Eyespots and color bands work to assist the operators in getting as close to the desired product that the customer is asking for.

“Eyespots” or “eyemarks” are the thin rectangles seen on polybags usually in the corner of the package.   The eyespots appear to have nothing to do with the design and in fact most times they do not. The eyemarks are printed on bags to allow the bag to to be machined to size.   The bag or bagging machinery has an electronic sensor or “eye” that sycs with the sealing element on the machine to provide a consistent bag size.    The sensor picks up the eyespot and triggers the machine to seal.

Why does’nt every bag have eyespots?  Some bag designs have a straight leading print edge that has a dark ink color that allows that portion of the print to double as the eyemark.

“Color bands” are printed when the design of the art calls for process print.  Process print is printing in “dots” that blend together to create various colors.  Process print allows for high-end photographic type images to be printed.  Process print is made up of 4 colors often referred to as CMYK printing.  (C–Cyan, M–magenta, Y–yellow, K–Black).    The color bands allow the color densities to be closely monitored during the press run to maximize the print appearance.

Why does’nt every process print package show color bands?   The color bands are always printed.  However, the bag size and design may allow the bands to be slit off prior to bag production.

We hope this helps.

Thanks for reading.