Bag closure manufacturers can now adopt a color change technology using a marking and printing additive that enables plastics to be marked using low power CO2 lasers. The additive is non-toxic and environmentally friendly, and is capable of producing an image when marked by a low power CO2 laser (approx 10W power). Once exposed to the laser on the production line, the additive undergoes a simple colour change to create a stable and high contrast date code. The introduction of this solution has also resulted in faster production run times for the company and removed the need for expensive consumables on the production line.

This new generation coding, marking and printing additive that enables plastics to be successfully marked using low power CO2 lasers, DataLase Masterbatch, has been initially used to date code bread bag closures for George Weston Foods (GWF). The bread is sealed using Kwik Lok all-plastics bag closures that are marked to provide information on cost, freshness and other package information. Traditionally Kwik Lok used thermal transfer printer to apply the data to the bread bag closures. However, finding that the information tended to rub off the closures, the company requested that Kwik Lok, Unimark (Markem's agent) and Sherwood Technology work together to provide an alternative date coding solution. By combining DataLase Masterbatch with low power CO2 lasers, GWF was able to produce high quality date codes that could not easily be removed from the closures.