This is a remix of my raised text version of these test prints with one addition as noted below.

These were created in preparation for a model I am working on that requires a large amount of raised text (printed in two colors via filament switching). I needed to determine the smallest practical text size that could be printed using a 0.4mm nozzle.

About the Prints 

In the first print, the number is the text height in mm, except that the line with the full set of numbers is size 3mm.

In the second and third prints, the first number in each line is the print size in mm; all subsequent characters on that line are in the same text size. Note that fractional sizes are given as decimals, using a bullet (•) as a decimal point (I find the bullet “prints” better than a decimal point).

For this set, I made one additional print : The V3BB version is the same as the V3B version, except that the text is bold.

UPDATE May 16, 2023 : I made some additional printing tests, with the results shown in the photo of six prints. The description of these prints (starting at the top left and going clockwise) is as follows :

1. Yellow on black (that is, light color on top of dark color)
2. Text in bold with top layer ironing*
3. Text in Bold - no ironing (this does not look much different from #2 above, but has a rougher feel)
4. Top dark filament layer height changed to 0.15mm - results in a lighter top layer
5. Top dark filament layer height changed to 0.15mm with top layer ironing - results in a lighter top layer but slightly darker than #4 above
6. Standard text with dark (black) top layer on top of light (yellow) bottom layers

*  No.2 gave the best looking results.

Print Instructions

I printed these in PLA; use the 3mf files provided. As noted above, I used a 0.4mm nozzle. I did not make any attempt to optimize the print parameters, so there is a good possibility that my results can be improved.

CAD

The OnShape 3D CAD files for this are here :

https://cad.onshape.com/documents/d753f5b654cb62d5d224e453/w/1a8c6ab21efb945889f229d2/e/54380099229ec32cb7b6ae74?renderMode=0&uiState=6461928d30af470c88b8f4ac