Engraving Acrylic with a laser creates amazing end products!
Let’s start off with the basics about acrylic. There are 2 main types of acrylic, Cast acrylic and Extruded acrylic. Both these acrylics are laser safe and fine to use with your laser.
Cast Acrylic is made by the manufacturer pouring liquid acrylic between a set of temper glass sheets. This liquid hardens and becomes the acrylic sheets. When engraved with a laser it gives a frosty appearance to the engrave. Cast acrylic cuts clean and has very good optical quality.
Extruded acrylic is made by the manufacturer adding acrylic pellets to an extruder which melts it down and then presses it through a die at high pressure to make a sheet. Most mirror acrylic and a lot of specialty acrylics are extruded acrylic. Extruded acrylic engraves with a clearer engrave then cast. It is also much softer so doesn’t need to be cut or engraved at as low of a speed as cast acrylic, in fact, extruded acrylic should be cut at the fastest speed possible and then taken right out of the laser and taken apart. So when engraving extruded acrylic, engrave first and cut second. The big reason for this is that if it is cut and left sitting during the engraving, it will most likely adhere back together in some places.
You can engrave and score acrylic on either the back or the front of the acrylic. If it is translucent, clear or mirror acrylic then engraving and scoring from the back by turning the acrylic over, reversing the image on the dashboard and engraving it will make it look a lot more polished and clean. It will give it a nice dimensional polished finished look. Here are some different examples of engraving. These little avocados were engraved differently. The one on the left was engraved from the front. It has a frosted textured appearance. The one on the right was engraved from the back. It has a cleaner shaper appearance.
You can also engrave on the front in a reverse engrave. This is when you engrave everything except the part you would usually engrave. So in this picture with reverse engrave, I engraved everything except the dragonflies, so they stand out and they shine with the mirror while the rest has a frosted look.
Some acrylic engraves with a nicer look if you defocus the laser’s lens first. This is done by manually setting the focus out of focus. For example, when I engrave ⅛” acrylic, I usually set the focus at .3” instead of .12”, for an even and smoother engrave. Trying different settings in small circles or squares to see what focus your laser engraves a certain piece of acrylic, is a great idea.
When engraving acrylic, you can remove the masking on the engraving side and put a thin layer of liquid dish soap on the acrylic before engraving. You can remove the masking on both sides if you would like, then cover both sides of the acrylic with a thin layer of dish soap. This will keep the acrylic clean and reduce any laser back flash. After you are done engraving simply rinse the piece off with water and dry.
We hope this helps with your engraving! Tag us @craftclosetsupply on social media so we can see what you make!