Paint Test Stick
thingiverse
These include a flat face, narrow corners, sloped edges, and increasingly narrow gaps to help test how a paint finish will actually look on a printed part. I'd love if you put a like on the post if these end up working well for you, and let me know if there's any extra features I should add. These are intended to be printed at the same settings as your main print, or you could print them at a .16mm layer height for a more finished look. (Extra note: if you print these on a textured build plate, it also includes a textured face for testing.)
With this file you will be able to print Paint Test Stick with your 3D printer. Click on the button and save the file on your computer to work, edit or customize your design. You can also find more 3D designs for printers on Paint Test Stick.