General Notes: There has never been an official statement on why Rolex moved from gilt dials to matte. They do exude a more utilitarian presence, are more robust, and were likely cheaper to produce – all things that Rolex aimed for when it made tool watches and not luxury goods. The matte dials take up the bulk of the production run for the 1675 (1966-1979) and the GMT-Master more generally (1966-1984).
There is much less to discuss about the printing process for these dials. First, a matte finished black background is printed on top of a metal plate. The text, minute, and hour markers are then printed on top in white, and then tritium lume is applied on top of the hour markers.
Below are the established iterations of the matte dial with links to each page, which you can also access through the drop down menu. Credit for establishing this system goes to Springer on TRF and Bill on PursitSPro.
Top Picture Credit: Bazamu