1970s Submariner - dial texture

Below is an example from a 1971 'meter -first' watch. The lacquer of the dial and the hour markers is granular, porous. It looks great . Which dials had this texture in the 1970s or did all of them and it is just a question of taking a picture with a good camera ? Or is it part of an aging process and thus depends on external factors ( humidity, exposure to the elements) ? Wuld be glad to be enlightened.
Alexander ( Paris)