(By the way? Do you think this is cool? Do you think huge LASERS are cool? Check out this contest that instructables is running right now: http://www.instructables.com/contest/hurricanelasers/ -- Grand prize is a laser exactly like the one we used on this project! My favorite machine in the lab! <3 Enter that contest!)
The effect is really cool, like a lace, except part of the shirt itself. We found that a 5% polyester/95% cotton blend worked best. The polyester seems to melt at the edges of the cuts, sealing them against fraying.
Cotton works as well, but care has to be taken not to fray the edges of the cuts.
See: lace.dxf if you want to cut one of these for yourself!
Step 1: Gather your materials
We also grabbed a piece of cardboard out of the scrap heap to keep the shirt rigid while we cut it.
Step 2: Cover the collar with something
Our first thought was plywood. The problem with this was that our laser has a "whisker" for zeroing the z-axis. Unfortunately, the whisker travels really close to the material while cutting, and this meant that it would catch on the plywood. NO GOOD!
Instead we decided to cover it with LOTS of tape (5 layers) and hope it worked.
It did. If your laser has room for it, do plywood, otherwise tape will work.
(You can see the tape in step 4. We forgot to take a photo of it, OOPS! In it's place, please enjoy this photo of me operating a bandsaw. This was for the piece of plywood we didn't end up using.)
Step 3: Tape the edges of the shirt
Step 4: Load the laser cutter
Our settings were:
This seemed to work really well! Our 5 layers of tape also protected the collar! Hooray!
Step 5: The result
Oops! This was because we started the cut at much too high of a power!