Tutorial Three:
Preparing a Window for Lettering with 1 Shot


Preparation of flat interior or exterior glass windows for lettering


Quality Glass Cleaner, Paper Toweling, a Single Edge Razor Blade


Thoroughly clean the window with glass cleaner (ammonia based glass cleaners work well, and you should avoid "glass and multi-surface" type cleaners) and "cheap" paper toweling. (The more expensive, name brands often contain skin softeners and absorbency enhancers that can leave behind a residual film that will negatively affect adhesion.)

Next, carefully scrape the entire area to be lettered with a single edge razor blade. There are several options of razor blade holders available that make this facet of the procedure both easier and safer.

Finally, reclean the area with paper toweling and glass cleaner.


When preparing to letter a window from the inside; always confirm the glass is not tinted, and that no tinting films are adhered to the inside of the pane. Always letter windows in temperature ranging between 60°F and 80°F for optimum results, and try to work on glass where there is less than 15 degree as difference between the outside and inside temperatures (both sides of the glass)

On exterior windows, never cover more than 40% of the glass with paint, and never use paint to "block out" the glass. Try to avoid filling large outside perimeters of the glass with paint (try not to work "edge-to-edge" with large graphics. Following these last few rules greatly reduces the chances of the window cracking or shattering as it absorbs heats from prolonged UV exposure.

This procedure and product recommendation has been proven to be effective in both a controlled lab as well as under standard shop conditions. It is always advisable, especially when trying a new procedure, to create a test panel first to try this application on prior to attempting to achieve optimum results on a given project. 1 Shot and Matthews Paint are not responsible for any failed attempts or product damages or failures caused by product use or misuse, lack of thorough understanding of and proper execution of the above procedure, or other unforeseen or unplanned for circumstances.