Achieving that "crystal clear" or "frosty white" look on acrylic is one of the most popular applications for a CO2 laser, but it requires a delicate balance of speed, power, and technique. Whether you are using a Redsail Desktop Engraver or an Industrial Elite Series machine, these professional settings and tips will help you eliminate melting and charring.

1. Choose the Right Type of Acrylic

Before you touch the laser, check your material. There are two main types, and they react very differently:

• Cast Acrylic: Best for engraving. It turns a crisp, frosty white when engraved. It’s ideal for awards and signage.
• Extruded Acrylic: Best for cutting. It remains clear when engraved and can get "gummy." Only use this if you are focused on clean edges rather than a frosted look.

2. The Golden Rule of Settings

For acrylic engraving, the mantra is: High Speed, Low Power.

• Speed: Aim for the higher end of your machine's capability (e.g., $300\text{--}500 \text{ mm/s}$ on a Redsail M6090E). High speed prevents the laser from lingering too long and melting the plastic.
• Power: Start low—typically between 10% and 20%. You only want to ablate the surface, not deep-cut into it.
• DPI (Dots Per Inch): For a smooth finish, 300 to 400 DPI is usually sufficient. Going too high (over 600 DPI) can put too much heat into the material, causing a distorted "bumpy" texture.

3. Focus is Everything

A standard focus gives you a sharp, thin line. However, if you want a smoother, whiter engraving on large text or logos, try defocusing the laser slightly.

• Lower the work table by 1–2 mm so the beam is slightly out of focus. This creates a wider beam that "blends" the engraving lines together for a more solid, frosted appearance.

4. Manage the Protective Masking

Acrylic usually comes with a paper or plastic film.

• Engraving: Remove the top layer of masking before engraving to prevent the adhesive from baking into the acrylic.
• Cutting: Keep the bottom layer of masking on to prevent "flashback" marks (honeycomb reflections) on the underside.

5. Air Assist: To Use or Not?

• For Engraving: Turn the air assist DOWN or off if possible. A strong blast of air can blow hot debris back onto the engraved surface, causing it to look "cloudy" or messy.
• For Cutting: Turn the air assist UP to blow out flames and ensure a flame-polished edge.

6. Pro-Tip: The "Soap Trick"

If you are struggling with "snow" or white dust sticking to the areas around your engraving:

1. Apply a very thin layer of liquid dish soap to the acrylic surface before engraving.
2. After the job is done, simply rinse with water. The soap prevents the hot dust from bonding to the clear parts of the acrylic.

Recommended Starting Table (For 60W-100W Lasers)

Final Thought

Always run a small Power Scale Test on a scrap piece of the same material before starting your main project. Every batch of acrylic is slightly different!

Would you like me to write a similar guide specifically for Wood Engraving or Leather Cutting?