If you have access to a laser cutter, these coaster make great gifts. They're easy to personalize and quick to make. I made it at the TechShop in San Francisco.
* Access to a laser cutter
* Blank glass coasters (I used Ikea Joker candle dishes)
* Painters tape
* Blank newsprint or butcher paper
Step 1: Design Coasters
You'll need to design your coasters using vector graphics software like Adobe Illustrator or CorelDraw. You can use the attached file as a starting point.
Start by outlining the coasters with the correct size circle. You may also want to mark out the lip of the coaster as a reference while you're designing. Then create your desired graphic. Reflect the graphic across its center so you can etch onto the back of the coasters and flip them over. After reflecting, double check that your work is still aligned correctly. Finally, copy your work in a grid so you can etch multiple coasters at once.
Step 2: Etch
Start by testing your design on paper. Tape a sheet of blank newsprint / butcher paper to the laser cutter bed. Try etching one of your designs on paper to see what it looks like. You'll need to use very low power settings and/or high speeds for thin material like newsprint. Just test the etching for now, do not vector cut.
When you're happy with your designs, vector cut all of the circles around the coasters into the paper and remove the centers. I used 90% speed and 10% power on our 60 watt Epilog for this.
Place your blank coasters upside-down into the cut out areas and run the etch! I used 60% speed and 90% power for the glass etch.
A few suggestions if your etches aren't consistent:
* Don't forget to refocus the laser between cutting the paper template and etching the coasters.
* You can run the job a second time. Note you may want to only etch problem areas the second time through.
* Some people have better luck putting blue painters tape or a thin, damp tissue over the glass being etched.
* If in doubt, run extra tests before you waste a full set of coasters.