Proper Use Of Razor Blades on Glass

One of the handiest tools we have is the Razor blade. It can be very helpful if used properly, dangerous and harmful if used carelessly.

The most common is the single edge blade, and the following will show you how to use them properly. When you unwrap your blade, use a permanent marker on one side to mark “Top”. From here on, the side marked “top” should never come in contact with your glass*. Your blade should always be used wet, lubricated with water, mild soap, or even glass cleaner. The blade should be held at a very shallow angle, so the handle portion stays 1/4″ to 3/8″ above the surface you are scraping. Razor blades should only be used in one direction, “pushing” debris in front of it. When pushing, everything the blade encounters will be harmlessly pushed ahead of it. Never pull the blade backward, as any debris it might encounter will be mashed between the blade and the glass, causing scratches. The proper technique is to push, lift, wipe, push, lift, wipe, until the job is done. All debris should be gently removed from the surface of the glass, remembering that there will be particles that can scratch. The blade should be wiped dry, and a light coat of lubricant such as WD-40 will help the blade to last longer. Always inspect your blade, and if you can see any flaws such as rust, nicks in the blade, or dried blood, throw it away. The cost of a blade is very small compared to damaging a project you have spent so much time on.


This is a microscopic view of a fresh new blade. The bubbly looking stuff is oil.

This is a blade that has been used to shave a man’s face for two days. With the naked eye, these differences are invisible, but are enough to cause scratches on glass.


* When a blade is run across a surface that has imperfections, the edge will turn up slightly, actually bending. You probably won’t be able to see this with your naked eye, but if you run the “top” side of the blade facing down, you will create scratches. Always keep the top side up.


Copyright 2013 – Arizona Glass Classes

June 2021
« Aug