What it means
Gauge does not work the same way in every industry
Most pool professionals cannot tell you the official difference between vinyl gauge and mil measurements. In industries like wire, shotgun barrels, sheet metal, and hypodermic needles, the thickness or diameter increases as the gauge decreases. For sheet vinyl used in pool liners, and for photographic film, the thickness of the material increases as the gauge increases.
For liner ordering, the practical question is simpler: how thick is the vinyl in standard units? Ameri-Brand researched mil and gauge standards and compiled information from manufacturers across the vinyl industry so the common liner sizes can be compared side by side.