How to Cut Glass

Cutting glass need not be left to the pros. With the right tools, patience and a delicate hand, you can easily learn how to cut glass at home. This beginner tutorial shows you how to trim pieces of large glass down to smaller sizes for window and door repairs, how to cut new pieces of glass for projects or just taking your craft game to the next level.

Two common tools used for glass cutting include a traditional glass cutter and a wheeled tile and glass nipper. Both tools are inexpensive and easy to use, but they come in handy for different purposes.

• Traditional glass cutters are best used for large sheets of glass, such as pieces you may be cutting down to size for replacement window panes or to right-size a piece for a picture frame.
• Wheeled tile and glass nippers are best used for precise cuts that are needed for stained glass or for trimming other hard-to-cut materials like mosaic tiles or porcelain.

In this tutorial, we’ll demonstrate how to cut large pieces of glass and then summarize best practices for other small, precise methods of cutting glass.

Step 1: Prepare Your Area

Setting up a large work surface that’s covered with an old towel or blanket helps to prevent surface damage and collect any unexpected shards of glass that result from the project. Wear safety goggles and gloves while working with glass.

Step 2: Clean Your Glass

Clean cuts start with clean glass. Spray glass cleaner across the surface and use a dry cloth or paper towel to remove dirt and dust before measuring and cutting the glass.

Step 3: Measure Your Cuts

Use a framing square or ruler to plan and measure your cuts. For the straightest of lines, clamp a straight edge to the glass.

Step 4: Apply Cutting Oil

While it’s not necessary to apply a cutting oil lubricant to the surface of the clean glass, it does make it a lot easier to slide the cutting blade and score the glass. The resulting edge is cleaner because the oil reduces friction.

You can also add a dab of cutting oil to your cutting blade for ease of use.

Step 5: Score the Glass

Line the glass cutter onto the surface of the material where you’ve measured and marked your cuts. Apply pressure to the cutter, rolling it away from you slowly along the straight edge.

Repeat these slow and controlled motions until the groove in the glass becomes pronounced (usually two-four passes depending on the thickness of the glass).

Step 6: Snap the Glass

Once you’ve scored the glass, you’re just about ready to snap it in half by hand. Place the cutter under the scored line to elevate the glass panel. Apply pressure with both hands at the far edges of the glass panel, on either side of the scoreline. When you fold the glass, it will snap in half. If it doesn't completely break, gently apply more pressure to encourage the glass to split.

Pass the sandpaper along the cut edges to ensure that any loose pieces are smoothed to prevent injury.

Tools to Cut Stained Glass Pieces

Trimming small pieces of glass to size for crafts is often a skill acquired for stained glass design. While you might use a traditional glass cutter like described above for initial cuts on larger pieces of glass, smaller cuts and precise trims are best handled by a different tool called a wheeled tile and glass nipper.

These trimming tools have carbide wheels that can cut precisely on direct lines without chipping or shattering the glass. Furthermore, it’s a great tool to use if you craft with other hard-to-cut materials like porcelain mosaic or ceramic tile, terrazzo, agate or seashells.

Cutting Glass Bottles

Cutting the end off a glass bottle takes more practice and finesse, but once you have the hang of it, it’s a great crafting skill to have. Like with large sheets of glass, it’s important to score a line around the edge of the bottle with a glass cutter, but avoid going too deep because it can crack the bottle. Instead, heat the scored groove with a candle and dip the hot glass into cold water. You’ll need to do this repeatedly, but eventually, the glass will cut clean at the line. Sand the edges of the glass before using it in any projects.