This GTP specifically addresses glass with paint on the backside, or the second surface of the lite, that is not exposed to direct human contact. There are many factors to keep in mind when determining the durability of back-painted glass. It is generally installed in an interior setting and protected from the exterior elements; however, it is still subject to an environment and application that requires the product to be durable. Back-painted glass may be exposed to mechanical or chemical attacks from cleaners, moist environments due to proximity of water or plumbing fixtures, exposure to ultraviolet (UV) light, heat through windows, and various installation methods. This document will provide some of the factors to consider when determining the durability of a back-painted product and provide direction for testing to determine a products' durability. The original version of this document was approved and published in January 2015. It was updated in November 2021.