Stained Glass Scoring and Breaking – an Art in Itself

By Dona Welch / December 17, 2019

Stained Glass Scoring and Breaking – an Art in Itself

Scoring and breaking stained glass is an art that you can achieve but not without some practice. All it takes is a little patience and you will soon be able to cut and break stained glass like a pro! The first thing to do when cutting stained glass is to relax when you are handling stained glass. It will make the work go much more smoothly.

Having the proper stained glass cutter is important. Various companies manufacture different types of stained glass cutters. They have cutting wheels of either carbide or steel. The wheel size and honing angles vary for use in specific types of glass cutting.

If you want the proper cutter for stained glass, it is best to go to a stained glass supplier. Cutters in hardware stores are generally made specifically for cutting clear glass.

Carbide wheels cost more but last longer than steel wheels. They will eventually get dull or even nicked and have to be replaced; but, you can replace the wheel only and not have to get a whole new cutter.

Stained glass cutters need to be lubricated to keep the wheels rolling freely. Most stained glass cutters, like Toyo or Fletcher pistol grip and pencil grip cutters, have a reservoir for lubricating oil which runs down a wick to the cutting wheel.

Stained glass cutters come with different handles which make the choice one of preference and fit. Once you have chosen your favorite cutters, it is best not to let other people use your cutter. They will put pressure on it differently than you which changes the balance.

Pencil grip stained glass cutters have a ball on one end which is used to tap the stained glass underneath the score line to begin a running break so that the glass can be pulled apart. Stained glass that has been scored can be pulled apart by hand; but sometimes, the glass pieces are too small to grip. Glass pliers can be used to separate the pieces that are too small to grasp.

Special “running” pliers are made for breaking straight lines. Some glass pliers have smooth gripping surfaces. Others have teeth for scraping off rough edges or shards of stained glass. Gripping one side of the glass firmly with your thumb along one side of the score gives the glass some stability. The breakers are used on the opposite side, pointing toward the score. You use a quick pulling away and down motion.

If your score is long, it is better to “rock” your pliers at one end to start a running break; then do the same at the opposite end of the score, then pull the stained glass apart.

A good score is done in one continuous motion. Starts and stops will only cause a bad score line which will end up in a bad break. Going over a score line twice dulls your stained glass cutter and makes a bad score line.

Stand up when scoring stained glass so that you can apply even pressure using the weight of your arm and leave your wrist free to follow curves. A metal ruler can be used to assist in cutting straight lines.

Be sure to hold the stained glass cutter straight up and down. If your cutter is leaning to one side, it results in a beveled cut, causing the stained glass pieces to fit poorly. Make sure you glass is clean before you cut it so that nothing interferes with a smooth score. Cut on the smooth side of the stained glass.