Metric thread gauge
thingiverse
Thread gauges, one from .9mm to 2mm the other from .45mm to .8mm. This could be a test for your printer. I was able to achieve .7mm before things got blurred. Using a brim got me to .9mm. Small enough that it's not much of a waste. Good luck.
Download Model from thingiverse
With this file you will be able to print Metric thread gauge 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 Metric thread gauge.