I have started to wash the windows at the Sherwin-Williams store on Main St. in Newark. They had not been cleaned by anyone in a long time, but now they want me to do the window cleaning once a month. The first time I did the cleaning I had to get rid of a lot of tape and sticker residue, which can be done in a few different ways. You can use a razor blade or scrub pads or heavy duty cleaner/chemicals. For this job I was able to use a new razor blade and clean off the residue easily. However, a razor blade can scratch some glass so it should not be use in all situations. If you do choose to use a razor blade to clean glass please make sure that it is a new blade. Old blades are dull and can get nicks and tiny bends in the blade and that can cause it to scratch the glass. Also, always wet the glass first before using the razor blade to help it glide across the surface. I found a nice little video on Ehow.com about the proper way to use a razor to clean glass. You can watch it by clicking here. If you get your paint and paint supplies from Sherwin-Williams let them know how the windows look.