Yes, they are mm and cm. I have another scale in inches, but it only shows down to 1/8" and that's not very small, so metric it is!
Here's my setup. I found this great copy stand that's the right size for this closeup work. I can get right in there, as well as pull back if needed.
https://www.ebay.com/itm/COPY-STAND-Mini-300-w-Floating-Magnet-USA-Made-A-Tool-for-Digitizing-Old-Photos/373015890629I purchased a couple of inexpensive LED lights that can stay plugged in via USB. They can also be mounted on a small tripod if I need some kind of awkward positioning. Mostly they stay flat and help illuminate the imprinted letters. I also have an inexpensive ring light on the end of the lens.
The stand has a mat on which magnetic strips can hold the paper. (they came with the stand) I printed out a scale ruler, cut it to size and hold it down with the magnetic strips. .
The camera is a Nikon D7100, lens is a Micro Nikkor 40 mm f/2.8. It has a very close focusing distance.
Because one of the major difficulties is depth of field on these small, rounded items, I need a very small aperture.
I use a timer (my remote is not working at the moment)
Aperture Priority
1/40
f/29
ISO 250 (Auto, with all of the lights)
I bump up the exposure by +1 on the bronze pens as they tend to be underexposed if I don't. I've tried different colored backgrounds to compensate for this, but white just works best all around.
Because the lens is getting close to a fisheye, on long pens I need to compensate for a very slight curve. I can do this in Lightroom. I first do lens correction, then use Transform/Guided, and draw lines along the horizontal and vertical ruler lines in the picture. This gets me the tiny bit of correction I need. Most people wouldn't even notice it, but now that I see it, I can't un-see it.
Ideally, I'd have a longer macro lens and zoom in, but this is the one macro lens I have.
Hope that was enough detail for you.
andrew