No need for a micrometer, 3m specs theirs. The Scotch® Super 33+ Vinyl Electrical Tape is 7mil or 0.007" thick.

As for the DMT plates, I'm pretty sure the spec on those is within 0.001" of total flatness. If you are really really concerned about flatness, you might as well spring for a Shapton Reference Plate, either the glass or cast iron based diamond one... either way you're looking at a significantly higher price.


Regards

Christian