These are cut out of sheets of vinyl material, sticky on the back, sold for $2 per foot at TechShop, which is pretty affordable for almost any design.
Step 1: Create the Design
* Cut out desired sprites
* Invert image so that sprites are black instead of white
* Scale them up (like 500%) with a nearest neighbor resampling
* Copy and paste into Illustrator
* Live Trace->Tracing Options
Path Fitting: 0.1px
Corner Angle: 85
Mode: Black and white
Ignore White: Checked
Click the Trace button
* Live Trace->Expand
* Clean up artifacts and incorrect lines
Step 2: Cut on Your Vinyl Cutter
To use your image in FlexiStarter, you need to export from Illustrator, either as an Illustrator 3 (.AI) file (not CS3, the ancient 3) or encapsulated postscript (.EPS). I recommend trying .EPS, then .AI if you have problems with the .EPS file. In this case, I used the .AI file.
Once you have it in FlexiStarter, you have to hit the "cut" button, which looks sort of like an exacto knife, and enter the size of your material, position the work etc. I haven't included the Flexistarter file, because I figure you'll have to resize it to your own dimensions etc, but I have included a .EPS file just in case you don't have Illustrator.
Step 3: Weed the Vinyl and Attach Transfer Paper
You want to just grab the corners of the parts you don't want and pull off the vinyl, making sure it doesn't accidentally grab onto the vinyl you do want. Then you can cut the individual sprites off the sheet.
After you do that, you want to put this transfer tape, which is paper or plastic with a sticky side (less sticky than the back of the vinyl) over the vinyl, so that you can apply the vinyl to a glass surface. I used the plastic type, but I prefer the paper type because it seems easier to remove. Once you put a layer of transfer tape on top of your vinyl, smooth it out with a squeegee to make it nice and flat with minimum bubbles.
Step 4: Put It on a Window or Somewhere
The simplest method is to just peel the non-stick backing off the vinyl, slap it on a window, squeegee it as flat as you can get it, then remove the transfer tape. I actually did this for a couple of the vinyl cutouts. The results were crooked and covered with bubbles. You can fix the bubbles a little with a pin and a squeegee, but the more complex method is probably better.
The more complex method is to peel off the non-stick backing, spray the window with a bit of Rapid Tac (or windex), put the vinyl on the window, position it, squeegee it, wait 3 hours, squeegee again, then remove the transfer tape. The reason to wait is that if you don't, peeling off the transfer tape removes the vinyl as well.
Step 5: Quick Discussion of Rapid Tac
* If you are using paper transfer tape, you can try to apply Rapid Tac to the paper transfer tape and let it soak through a bit, which should reduce the adhesion between the tape and the vinyl, making it easier to remove.
* You can also clean the window with Isopropyl Alcohol to make the vinyl stick extra well. This should remove residue left by Windex or Rapid Tac.
* I recommend using these tiny yellow squeegees from Tap Plastics, you can get a fair amount of force going on them since they're tiny, and they have these ridges that help you hold them.
Quick TechShop story: I was having trouble with the Rapid Tac and was asking a TechShop member if he had any tips. An expert on applying vinyl who worked at Tap Plastics happened to be standing nearby. He overheard my questions and walked over to gave me all sorts of vinyl applying tips. Thanks Tap Plastics guy!
While I can't guarantee experts will be standing around whenever you have questions at TechShop, it is pretty impressive how many guys there just happen to know all sorts of stuff about making things.