– The thickness of a single sheet of paper, expressed in units of thousandths of an inch. Normally, paper caliper should not have more than a + or – 5% variance within a sheet. In general the greater the caliper, the greater the paper weight. 80 grams writing paper has a caliper of 4 (a single sheet is 0.004 inch thick).

– A device used to measure distances (such as the thickness of a sheet of paper).