WRITING

Concerning the writing of the Color Data Matrix, various types of media have been considered. The following table shows the tested materials and techniques used for the writing:

Media types	Writing technology
printer/photocopying paper	Inkjet printing
Photo quality paper	Laser printing;
Plastic	Off-set printing
Metals (bulk); brass, stainless steel,titanium, gold.	Laser
Metals (coatings): chromium, titanium and zirconium deposited by techniques under vacuum in a reactive atmosphere, ruthenium, gold, palladium	Laser

As far as printing on metal is concerned, a laser marking specially purchased from Sigma Laser by Top Finish 2002 Srl has been used.
The coloring of the metal is due to a phenomenon of surface oxidation, induced by the energy transferred to the metal by the laser beam.
The colors obtainable vary from metal to metal, as shown in the figure below