Aug
20

Laser-Cut Coasters

I used the laser cutter to make a set of coasters with stylized pictures of a couple whose wedding’s coming up.

The end result!

The pictures are etched in paint on plexiglass.

I got a piece of 4mm thick plexiglass, and cut it into squares a bit larger than I wanted the coasters to be using the laser cutter (power 100, speed 5), and then I painted them black. After a previous disaster involving spray paint, I used acrylic crafting paint.

It turns out layers of spray paint dissolve each other

Once the paint was dry, I etched the pictures in using the laser cutter. I started by converting photos to monochrome bitmaps, and importing them into the LaserCut software, but this led to pixelated-looking images.

Too pixelated!

The image in the attempt above is also reversed, because I forgot that when engraving, black areas in the laser-cut software are the ones that get engraved (so turn white).

Agnes suggested smoothing out the pictures using Adobe Illustrator (CS), which improved the engraving substantially. We then imported the smoothed files using Corel, which can convert to the DXF format which is supported by the laser cutter. Afterwards, I figured out that Corel Draw supports similar smoothing features, so the rest of the images were smoothed and exported in Corel only.

I tested engraving these images using the laser settings that had worked with spray paint (speed = 300, power = 20), and it turned out well. The acrylic paint doesn’t seem to be that sensitive to the power setting of the laser. I found that so long as the power was in the right ballpark, the paint from the etched areas would come off when I washed the plexiglass with soap and water. This resulted in very clear etching.

It worked!

I then painted the backs of the coasters to add colour.

Painting!

Before and after

I then used the laser cutter to trim around the edges, removing any paint I had dripped around the edges while painting.

I tried putting corkboard on the back of the coasters, but found that corkboard doesn’t cut well (and smells really bad) in the laser cutter, and it crumbled when I tried to cut it using scissors or a knife. So I ended up cutting pieces of white acrylic and gluing them to the back with crazy glue.