Bar code bearing medium.

摘要

A bar code printing medium 10 which may be applied to an article (16), the medium 10 having an upper surface on which at least one bar code 12 has been printed, characterised in that at least one bar code 12 is covered with a colored transparent film 14 having a selective transmittivity in a predetermined wavelength region. The film (14) can be a good or bad transmitter is the wavelength region of an associated bar code reader (15) relative to the general optical wavelength region thus making the film covered code (12) easier or harder to read by a bar code reader (15) relative to the human eye and this difference can be removed by stripping off the film (14). <IMAGE>