Acrylic is simple to work with, comes in a wide variety of shapes and sizes, and can be relatively inexpensive.
Acrylic
Next to wood, acrylic is the second most popular material for laser cutting and engraving. It is easy to both engrave and cut, comes in a wide variety of shapes and sizes, and can be relatively inexpensive.
Acrylic comes in two forms: cast and extruded. Cast acrylic is used for almost all engraving purposes, because when it is engraved, it produces a white, frosty look that makes for a clean contrast against the clear material. Extruded acrylic remains clear when engraved and does not produce much of a contrast. On the other hand, it is ideal if you are only going to vector cut. The material also has a lower melting point, which produces an almost flame-finished edge when cut with the laser.
Tips and techniques
- Most acrylic is reverse engraved on the back side of the item. This produces a “look-through effect” from the front of the surface. It is recommended you remove the top protective cover from the acrylic before engraving. Leave the bottom protective layer on, so it remains intact, to prevent scratching while handling the material.
- Remember to reverse or mirror your artwork prior to starting an engraving project on acrylic.
- Engrave the acrylic at a high speed and low power. A small amount of power is all it takes to mark it, and if you set your power level too high, you run the risk of distortion.
- Set the focus so the acrylic is slightly further from the lens than normal. Lowering the focus by approximately 1.6 mm (0.06 in.) will soften the engraving, so each individual raster line blends better with the lines above and below, producing a smoother, more pleasing look.
- A large number of products are painted on one side to add colour to the clear acrylic piece. You can engrave directly through the paint into the acrylic for a nice presentation effect. Leave the speed the same, as if you are engraving clear acrylic, and increase the power about 10 per cent to engrave through the paint. Applying too much power to the paint will melt it and cause distortion.
- Cutting acrylic is usually best achieved with relatively slow speed and higher power. This combination allows the laser beam to melt the edges.
- Acrylics generally require only a single pass to cut, but thicker pieces may need two passes. It is sometimes necessary to mask and dampen the acrylic before cutting.
- Acrylic is very flammable. You should never leave your laser unattended when vector cutting any material.
Glass
When it is etched or engraved, glass produces a classic and sophisticated look, which is why it is a popular material for laser engravers. When a laser strikes glass, it fractures the surface, but it will not engrave deeply or actually remove material. However, this fracturing is what produces the sought-after frosted look.
Unfortunately, if the glass is not protected during the engraving process, the fracturing can cause flaking and unwanted chipping of the engraved area.
The composition and quality of glass varies greatly, which makes it challenging to predict the effect you will achieve. It is recommended to experiment with a variety of glass types, as well as speed and power settings.
When a laser strikes glass, it fractures the surface, but it will not engrave deeply or actually remove material. This fracturing is what produces the sought-after frosted look.
Tips and techniques
To produce a smooth, frosted finish with minimal chipping, use the following techniques to protect the glass while engraving:
- Using your finger or a paper towel, apply a thin coat of liquid dish soap over the area to be engraved.
- Place the glass into the engraver and laser through the soap while it is still wet. The dish soap is often all that is needed to protect the glass.
Alternatively, you can use this method:
- Cut a piece of newspaper or paper towel a little larger than the area to be engraved.
- Completely soak the paper with water, then wring it out. You can also place the paper on the glass first and use a mister to soak the paper.
- Apply the paper to the glass and smooth it out, so there are no wrinkles.
- Place the glass into the engraver and laser through the paper while it is still wet.
- Remove the glass, discard the remaining paper, and clean the glass.
Using the techniques above will help ensure your glass engraving projects turn out as desired every time.
