The usual method to replicate these is to use Slaters plastic alphabet characters, but I wondered if it would be possible to replicate them using a DLP printer.
These letters are 2.81mm tall and 0.5mm thick. The idea was to try and make a sprue from which letters could be selected.
I've had to spray them with grey primer as I'm currently trying out a translucent resin for making tank optics.
They were printed flat to the bed, so the next attempt will be at 45 degrees to see if that helps with the resolution.
I've had better success printing them onto a flat support panel and got that down to 0.2mm thick, with much better resolution on the letters.
However, the problem then becomes getting the part off the supports without destroying it. Still working on that one

At least with DLP you can cover the bed with duplicate parts and it doesn't affect the printing time.
Adrian.