peel ply is dacron cloth. Just like "real" covering material.
It is sold to be used in composite fabrication.
I can pull an old aircraft spruce catalog where it will be listed in two different sections
As peel ply, and also as a lightweight covering material. Right there with the name brands.
Both sections have the same part number and price. The cloth is uncertified and intended for ultralights or other lightly loaded aircraft.
As a peel ply, it is used with the intention of being removed. example:
We have a composite which will require additional layups or future epoxy to another item.
We are done with the original layup and the last item while still "wet" is a layer of peel ply where called for. After curing I can pull the peel ply off as the epoxy won't stick to it. It leaves behind a fabric patterned rough surface ready for future adhesion.
As a covering material, it acts just like the heavier coverings. Heat shrinks, paints glues the same process as the more expensive material.http://www.aircraftspruce.com/catalog/cmpages/peelply3.php
Sure would have been easier to just link, but for a few years, they hid the covering aspect?