Process Date: March 2000

Marked with 2 watts of power at 20" per second
Used for displays where the mark will be read under varying light conditions, such as automotive displays, hi-fi systems, and telephones, "Day and Night" design attempts to optimize the readability or visibility of a display in both light and dark ambient lighting conditions. Under light conditions, the display is black with white contrast, and under dark conditions, back illumination creates a contrast. The unique mark is achieved by removing the top layer of  two-layer plastic to reveal a white transparent underlayer.

The key  to successfully  marking the material is to remove the top layer, while leaving the lower layer untouched. The darker top layer must not fuse to the lighter underlayer, as fusion of the layers will discolor the underlayer, resulting in a faded appearance. It should also be noted that the underlying white material must be of a suitable thickness so that it is not penetrated when removing the top layer.

Currently, Nd: YAG lasers are more commonly used for this application. However, by using a very low laser power with high resolution, the CO2 laser is capable of producing comparable results on this two-layer material.