To start a score, place cutter OFF the top of the glass, press down and pull the cutters towards you until you come OFF the bottom. Some people like to pull when they score the glass, some people like to push starting at the bottom. Try both and see which way works best for you.
Only cut once. Never correct a mistake by cutting again. Never go over the scored line a second time. Not only will it fail to cut the glass, it also can dull your cutter. If you have to, turn the glass over and cut on the other side.
If you want to use oil, then just a touch of lubricant. Some people cut without oil, others lubricate their cutters generously. For fusing, the best amount of oil to use is the least amount you can use and still keep the wheel from freezing up. Excess oil means more time cleaning the glass before fusing. Also, using mineral spirits is a good idea; they are inexpensive and also burn off cleanly when firing. Ethyl alcohol is recommended to clean the glass. It smells better than the other kind, but is extremely flammable. ALL oil must be completely cleaned off. If we were a major art glass company dealing only in glass and making beautiful and very large works of art, we might use oil, but for a pyop doing jewelry, tiles, fritters, small plates and bowls, we haven’t found it necessary to recommend using oil when cutting. However, if using the round glass cutter to make circles, we do recommend a TINY amount.
If you wait too long, the score will begin to "heal" and it will be difficult to get a clean break.
The key to good breaking, just like good cutting, is practice. So use scrap window glass until you feel comfortable with the cutter and how to use it.
Be careful when disposing of glass. Another safe approach besides the one we already mentioned, is to wrap the small slivers and chips in scrap newspaper and tape together. This quickly tidies up the workplace and also avoids accidental cuts.
Use only standard thickness glass if planning on a base without a cap when making jewelry pendants. If using thin as the base, either put another clear thin on top and then frits, dichroic, stringers, between them or on top. There is a Thickness Rule in glass – all glass wants to go back to ¼” thick when fired. If you use only one thin piece, which is about 1/8” thick, it can cause the edges to jut out or spike away from the center if you try to full fuse.
Keep all thick decorative pieces away from the edges of the base or they will push the edges out as well.
If using a transparent, Iridized glass as your base, put the Iridized side face down on the fiber paper. Your piece will look much prettier and you will have less chance for bubbles.
Always fuse and slump in separate firings. Trying to do them both in one firing will cause major distortions and bubbles and can break not only your glass, but the glass mold.
Don’t slump or fuse pieces too close to the lid with elements. Allow at least 4” for slump and 5” or more, for fuse, or else, slow the rate of the heating.
Experiment – be creative – learn from you mistakes – take chances!