Mils vs. Microns
Mil - A unit of measurement in the English system that is measured in thousandths of an inch.
(i.e., .001″ = one thousandth of an inch or 1.0 mil)
Micron - A unit of measurement in the metric system that is equal to one thousandth of a millimeter.
(also called a micrometer, abbreviated ‘μm’)

The M-Shop uses only the English Imperial/US system (inches, feet, etc.).
All measurements taken in microns must be converted to thousandths of an inch. 

For the exact conversion:
Mils to Microns: (Number of Mils) x 25.4 (i.e., .75 mil = 19 microns)

Microns to Mils: (Number of Microns) / 25.4 (i.e., 14 microns = .55 mil)