The Polymer skin, half gap thickness (top) result provides you with a measure of the polymer skin thickness on the top side of the elements.
This result is generated from a Gas-assisted Fill+Pack analysis using Midplane analysis technology.
For solid polymer sections where no compressed gas has penetrated, the value is equal to the half-gap thickness of triangular elements, or radius of 1D (runner elements).
For hollowed sections where gas has penetrated, this variable is equal to the half gap thickness or radius multiplied by the polymer skin fraction value.