This traditional, European-style spackling blade is not just a single-use tool. It can also be used as a painting tool with Pure Linseed Oil Paint to help create perfectly straight sight lines and sharp corners on windows.
When painting with linseed oil paint using Allbäck's WindowCraft techniques:
Paint all coats of linseed oil paint out onto the glass.
Use a sponge to wipe the surface with linseed soap and water to soften the dry paint a little and make it easier to manipulate.
Set the Spackling Blade as your trimming guide, and trim the paint along your guide with a glass scraper in order to achieve crisp, straight paint lines and sharp corners on the glass every time.
This technique allows the painter to work more quickly without having to cut in straight lines by hand, and it also maximizes the protection quality of the linseed oil paint at the most vulnerable part of the window assembly: where the putty meets the glass.