How to Perform Transparent Acrylic Engraving?

Background

Are you interested in creating stunning, frosted designs on transparent acrylic? Transparent acrylic engraving using a diode laser is a simple, beginner-friendly process that results in beautiful, glowing effects when illuminated. This blog focuses on engraving patterns like SpongeBob on acrylic to make custom lamps, but the techniques apply to any design. 

Why Engrave on Transparent Acrylic?

Transparent acrylic (also known as plexiglass) is ideal for laser engraving because the laser creates a frosted, etched surface that diffuses light beautifully. When backlit with LEDs, it produces a soft glow, perfect for lamps, signs, or decorations. This method uses black cardstock underneath to absorb the laser, eliminating the need for paints or sprays. It's cost-effective, quick, and safe for home use.

Materials Needed

1. -Transparent acrylic sheet (at least 3mm thick; e.g., 15cm x 20cm rectangle for a small project).
2. -Black cardstock (slightly larger than the acrylic to place underneath).
3. LED lamp base (USB-powered, with a slot matching the acrylic thickness).

Tools Required

1.  NEJE Diode laser engraver
2. LightBurn or NEJE software
3. Damp cloth or alcohol-water mixture (for cleaning).
4. Scissors or craft knife (to cut cardstock).
5. Tape or clips (to secure materials).

Note: Ensure your workspace is well-ventilated to handle any smoke.

Step 1: Prepare Your Materials

1. Peel off the protective film from the acrylic sheet.
2. Cut black cardstock to be slightly larger than the acrylic.
3.  Place the acrylic on top of the cardstock, ensuring full contact with no gaps. Secure with tape or clips.

This method allows the laser to pass through the transparent acrylic and reflect off the black cardstock, creating the frosted engraving effect.

Step 2: Set Up the Design and Software

1. Secure the layered materials on the NEJE laser engraver's working area.
2. Open LightBurn software and import your picture or vector design like below. 
3. Adjust the laser focus to the bottom surface of the acrylic.
4. Recommended settings for a 20W laser: Speed 13000 mm/min, Power 28%. 

Step 3: Perform the Laser Engraving

1. Start the engraving and use an exhaust fan or air purifier for smoke.
2. Remove the cardstock and let the acrylic cool naturally.

The result: A frosted pattern etched into the back of the acrylic.

Step 4: Clean and Assemble

1. Wipe the engraved surface gently with a damp cloth or alcohol mixture to remove residue.(Avoid scrubbing to prevent scratches.)
2.  Insert the engraved acrylic into the LED base. Connect to power and enjoy the glowing design.

Tips and Troubleshooting

• Uneven engraving: Check material adhesion or laser focus.
• Customization: Experiment with speeds/power for deeper etches or try different patterns.
• Common mistakes: Using extruded acrylic (prone to melting) instead of cast.

Conclusion

Transparent acrylic engraving is an accessible way to create illuminated art. With practice, you'll master laser settings for flawless results. If you're engraving a SpongeBob or similar pattern, share your creations online for inspiration!