Cast vs Extruded Acrylic: Know What You Are Buying

Cast acrylic laser cuts with a bright, flame-polished edge and engraves a frosty white - the classic signage look. Extruded acrylic is cheaper and engraves almost clear, but edges come out slightly less glossy and it is more temperature-sensitive. For premium retail display and awards, choose cast. For bulk industrial parts, extruded keeps costs down. Label your stock so the shop never guesses.

Dial In Power and Speed With a Test Grid

Start conservative: for 3 mm cast acrylic on a 100 W tube, try around 18-22 mm/s at full power, then step speed up or down from your test grid. A correct single pass always beats two fuzzy passes. If the bottom edge shows ripples, slow down; if the top edge rounds over, drop power and raise speed.

Air Assist: Less Is More

Acrylic is one material where heavy air assist hurts. Strong airflow blasts the melt into a frosted edge and can ignite the kerf. Use low, steady air - just enough to keep the lens clean. Many acrylic specialists run the pump at minimum or pulse it off during cutting.

Masking Beats Post-Processing

Apply low-tack transfer paper to the face before cutting to block smoke residue. Paper costs minutes and saves hours of scraping. For engraving, mask the area and rub a little dish soap under the paper to get an even frosted result without halo.

Support the Sheet the Right Way

Lay acrylic on raised pins or strips so the beam exit side never touches the slats - reflected energy scorching the underside is the most common cause of mysterious edge burn. Never cut acrylic resting flat on a honeycomb bed without standoff.

FAQ

Why are my edges frosted instead of glossy?

Usually extruded acrylic, too much air assist, or a worn lens. Confirm the material first - no setting fixes a frosted edge on extruded stock.

Can a CO2 laser cut 20 mm acrylic?

Yes with 100 W+ in multiple passes, but edge quality drops on the second pass. For production at that thickness, step up to a higher-power flatbed machine.

Put the Tips to Work

Our desktop engravers handle acrylic craftwork beautifully, while the mini engraver range suits small signage startups - both cut cast acrylic with showroom edges when set up as above.

Still comparing suppliers? HF Laser maintains a detailed catalog of CO2 laser cutters, engravers and auto-feeding machines that makes side-by-side comparison easy.