GMNA GM6256M PDF

This standard gives the requirements of the anodized aluminum which has been colored black by electrolytically depositing cobalt mineral salt at the base of the anodized layer and then sealed. It also gives durability requirements of the laser bar coded plates made from the material. The objective is to make certain that the purchased material will respond properly to the laser and make bar codes that are readable by typical scanning devices for 20 years.