How to Cut Acrylic (Plexiglass) Signs at Home: A Complete DIY Guide

Acrylic—also known as plexiglass or polymethyl methacrylate (PMMA)—has become the go-to material for DIY sign makers, hobbyists, and small business owners. It's lightweight, shatterproof, and significantly cheaper than glass while offering similar clarity. But cutting it cleanly requires understanding how the material behaves and selecting the right tools for your project.

This guide covers everything from blade selection and heat management to edge finishing and safety—so you can achieve professional results on your next custom acrylic sign project without ruining expensive material.

What makes acrylic different from glass or wood?

Acrylic is a thermoplastic. That single fact drives almost every cutting decision you'll make. Unlike glass (which shatters) or wood (which chars), acrylic melts when it gets too hot. Run your saw too fast, use the wrong blade, or push too hard, and you'll watch the material melt back together behind your blade—creating a welded seam instead of a clean cut.

The material comes in various thicknesses, typically ranging from 1/16" to 1/4" for most sign applications. Thinner sheets (under 3/16") can be scored and snapped by hand. Thicker panels require power tools—and more attention to heat management.

Which cutting method should you use?

The right tool depends on sheet thickness and cut complexity:

• Scoring knife: Best for sheets under 3/16", straight cuts only. Requires 5–10 scoring passes and clean snapping technique.
• Circular saw: Ideal for straight cuts on any thickness. Requires a fine-tooth blade (60+ teeth) and slow, steady feed rate.
• Jigsaw: Perfect for curved cuts. Use a 14 TPI metal-cutting blade. Expect some edge roughness that needs finishing.
• Router: Excellent for precision work and edge profiling. Use a straight bit at reduced speed to prevent melting.
• Table saw: Best for production work with multiple identical cuts. Requires proper blade and fence setup.

How do you choose the right blade?

Blade selection is the difference between a clean cut and ruined material. According to ACRYLITE's fabrication guide, optimal blade specifications for acrylic include:

• Tooth count: 60–80 teeth for a 10" blade; 80–100 teeth for 12–14" blades
• Tooth design: Triple-chip grind (TCG), which alternates between beveled and flat-top teeth to reduce heat
• Material: Carbide-tipped for longer life and cleaner cuts
• Surface feet per minute (SFM): 6,000–14,000 ft/min for optimal cutting

Brands like Freud Diablo, DeWalt, and Lenox make excellent acrylic-cutting blades. For jigsaws, a 14 TPI metal-cutting blade works well.

How do you prevent acrylic from melting?

Heat management is critical. The solution involves three approaches working together:

1. Use the right blade: Fine-tooth, carbide-tipped, triple-chip grind.
2. Control your speed: Reduce saw RPM if possible. Feed material at roughly one inch per second—slower for thicker sheets.
3. Minimize blade clearance: Set the blade to extend just 1/8" to 1/4" beyond the sheet thickness. This reduces friction and heat buildup while improving chip control.

Some professionals spray water on the cut line during operation, though this requires careful setup to avoid electrical hazards. A simpler approach: make multiple shallow passes rather than trying to cut through in one go.

What preparation steps matter most?

Proper setup prevents most cutting failures:

• Leave the protective film on. That paper or plastic covering protects the surface during cutting and handling. Remove it only after all cutting, drilling, and finishing is complete.
• Support the entire sheet. Any unsupported areas can flex during cutting, causing cracks or uneven cuts. Use sawhorses with boards laid across them for larger sheets.
• Clamp securely but not too tight. Excessive clamping pressure can crack the material.
• Mark carefully. Use a grease pencil, fine-tip marker, or painter's tape. For complex shapes, create a cardboard template first.

How do you score and snap thin acrylic?

For sheets under 3/16", the scoring method works well:

1. Place your straightedge along the cut line.
2. Score firmly with a plastic scoring knife (or the dull side of a utility knife), making 5–10 passes along the same line.
3. Flip the sheet and repeat on the opposite side.
4. Position the score line directly over the edge of your work table, with the bulk of the sheet supported.
5. Apply firm, even downward pressure on the overhanging section—the sheet should snap cleanly along the score line.

What is the correct technique for power saws?

Let the tool do the work. Feed the material slowly and steadily, without forcing it. Listen to the sound:

• High-pitched squeal: You're going too fast or the blade is dull.
• Smooth, consistent hum: Proper cutting speed.

A good rule of thumb: move at about one inch per second for a circular saw, slower for thicker material. If you're pushing hard to make the saw move, something is wrong.

How do you finish edges for a professional look?

Even the cleanest cut leaves edges that need finishing. Raw-cut acrylic edges are typically rough with micro-scratches that catch light and look unprofessional.

The finishing process:

1. Start with 120-grit wet sandpaper. Keep the paper and edge wet to prevent heat buildup. Sand in long, even strokes along the edge, not across it.
2. Progress through finer grits: 220, 320, 400, and finally 600-grit. Each step removes scratches from the previous grit.
3. For a polished edge: Finish with a plastic buffing compound and an electric drill fitted with a buffing wheel. Work in small sections, keeping the material moving to avoid heat buildup.

The result is a crystal-clear edge that looks professionally flame-polished.

What safety precautions are essential?

Cutting acrylic generates fine plastic dust and small shards. Always use:

• Safety goggles (not just glasses—goggles that seal around your eyes)
• Dust mask or respirator when using power tools
• Tight-fitting work gloves for handling cut sheets (avoid loose gloves near power tools)
• Good ventilation since cutting can release fumes, especially if you overheat the material

Secure your work piece properly. A sheet that shifts mid-cut can bind the blade, causing kickback or shattering the acrylic.

When should you consider polycarbonate instead?

While this guide focuses on acrylic, polycarbonate (brand name Lexan) is worth considering for certain applications. According to Acme Plastics, polycarbonate has 250 times the impact resistance of glass, compared to acrylic's 17 times—making polycarbonate roughly 15 times more impact-resistant than acrylic.

The trade-offs:

• Polycarbonate: Much more impact-resistant, easier to cut without cracking, more forgiving of mistakes. But it scratches easily, yellows faster under UV exposure, and costs more.
• Acrylic: Better optical clarity, better UV resistance, easier to polish. But it's more brittle and can crack if stressed.

For outdoor signs in rough neighborhoods or high-impact applications, polycarbonate is often worth the premium. For most protected indoor signage with clear display requirements, acrylic is the better choice.

What are the most common mistakes?

1. Wrong blade or too much speed: Causes melting and welded edges. Use fine-tooth blades designed for plastics.
2. Removing protective film too early: Leave it on until all work is complete.
3. Inadequate support: The entire sheet must rest on a flat surface except the small section being cut.
4. Forcing the cut: If you're pushing hard, something is wrong—dull blade, wrong blade type, or feed rate too fast.

Ready to start your project?

For DIY projects, these techniques will help you achieve clean, professional-looking cuts. For larger projects or when precision matters—especially for business signage where first impressions count—consider having professionals handle the fabrication.

SF Bay Signs offers custom acrylic signs cut to your specifications with polished edges and professional finishing. We can also handle installation throughout the Bay Area. Start your project to get a quote.

FAQ

Can I cut acrylic with a regular wood-cutting blade?

While possible, it is not recommended. Wood-cutting blades have fewer teeth and generate more heat, leading to melted edges and rough cuts. Use a fine-tooth blade (60+ teeth) designed for plastics or non-ferrous metals for best results.

Why does my acrylic crack when I try to snap it?

Cracking usually occurs from insufficient scoring (make 5–10 passes), scoring too close to the edge, or applying uneven pressure when snapping. Ensure your score line is deep and consistent, and fully support the sheet before applying breaking pressure.

How do I prevent acrylic from melting when cutting?

Use a fine-tooth blade, reduce cutting speed, and feed the material slowly. Some professionals spray water on the cut line to keep it cool. Making multiple shallow passes instead of one deep cut also helps manage heat.

What is the difference between acrylic and polycarbonate?

Acrylic offers better optical clarity and UV resistance but is more brittle. Polycarbonate has roughly 15 times the impact resistance of acrylic, making it better for high-traffic or vandal-prone locations, but it scratches easier and yellows faster.

Can I use a jigsaw for straight cuts?

Yes, but a circular saw or table saw will give you straighter, cleaner cuts. Jigsaws are better suited for curved cuts or situations where you need to start a cut in the middle of a sheet.

How thick of acrylic can I cut by hand?

Sheets up to 3/16" thick can be scored and snapped by hand. Anything thicker requires power tools for reliable results.