Reddit mentions of School Smart 8-1/2 x 11 in Copier Film Without Sensing Strip, Pack of 100, Transparency - 079880

The term you're looking for is transparencies.

Get plastic sheets, like overhead transparency plastic. link

Then use spray-on glue to attach it to the shirt. link

Spray the back side of the plastic, wait for it to get tacky, then apply it to the shirt. This is actually how I learned to make stencils, so I can 100% confirm that it works. You just need to be a little careful pulling the plastic up to ensure nothing in the stencil breaks. Goo-gone the back of the stencil after you're done to remove any glue residue, and you're ready to go for next time.

Hi! I found the same problem and I switched to plastics.

You can see the process here:
http://imgur.com/a/BgQNT

What I use is here:
http://www.amazon.com/universal-laser-printer-transparency-65125/dp/B007X8HS9S

But alternatives could be found easily:
http://www.amazon.com/School-Smart-Transparency-without-Sensing/dp/B003U6KYO8/ref=sr_1_1?s=office-products&ie=UTF8&qid=1405623900&sr=1-1&keywords=transparency+film


You can also buy plastic folders or, my personal favorite, plastic folder dividers (that's what Gengar is made out of) for a more "solid" stencil but they are REALLY hard to cut. I made Gengar with scissors and a box cutter!

how about?
I got these, used double sided tape instead of the adhesive because I'm paranoid. Alternatively, I have a shitload of these from when the office was going to toss them. I use them as stencils, but they'd work too.

by the way:

http://smile.amazon.com/School-Smart-Transparency-without-Sensing/dp/B003U6KYO8/ref=sr_1_1?ie=UTF8&qid=1419275430&sr=8-1&keywords=overhead+projector+sheets

Thanks dude! And, yeah that's an awesome design, I think it'd make a cool deck too.

I'll let you in on a secret that took me forever to figure out: the best way to make masking / stencils is to get yourself some transparency sheets, like the kind used for overhead projectors in school, and then take a marker and draw what you want to spray through (best way to make stencils). Then take a 'wood burning kit' (which is just a low-heat soldering gun pretty much) and use it to "trace" your lines on the transparancy sheet, do it light and quick and it'll cut the parts out that you want - afterwards you'll be left with a mask or stencil that's much stronger than paper, easy to clean, and the wood engraver allows you to make more detailed and smoother cuts than if you were masking with tape, or cutting out of cardboard or card stock.

When you finish your painting, you'll want to give it a light coat of clear spray finish, and when that dries hit it with a coact of actual clear coat - I use minwax - that''s 'satin' (which is their way of saying 'matte') listed there but I prefer mine to be gloss. It's important that you hit it with the spray finish first, because it'll seal the paint, and the minwax may cause it to run if you don't. I use a lot of markers in my paintings and minwax will absolutely make them bleed and run if I don't seal them first.

You also want to seal it because the acrylic will easily chip off the deck

Like I said, also be aware that painting on a deck is A LOT different than painting on canvas, the deck will cause the acrylic to paint much faster than canvas so you lose that 'wet period' you normally have to blend paint.

Good luck, post a picture when you finish it! And feel free to drop me a line if you have any other questions.