I use blue painters tape. There are a couple of other versions (the price increases as the adhesion reduces) as well - they’re different colors to keep them separate.
There’s also tape that’s specific to masking but it’s more expensive than I’m willing to spend and has to be ordered over the web vs being able to run to the hardware store for a wide roll of painters tape.
That’s a good idea. I’ll try that
I wonder if you could just stretch a sheet of one of those pseudo-adhesive plastic wraps over, or if that would end up a terrible mistake. Or maybe parafilm…
I suspect it would just melt to your product
Those turned out amazing. Great work being done on the GF. I will be bookmarking that site. I have a clock to make with a pic on it. That site will help for sure.
That website looks awesome, though here is a way to do it in Adobe Illustrator if you need more control!
Oh, saving this link, thanks!
Yep…linked! Thanks! 
Maybe frisket masking for airbrushing might work? There are also paper masks sold for signmaking, couple manufacturers that come to mind are R-Tape and MacTac. They come in various levels of tackiness and most of them will release when soaked with soapy water.
I will definitely be doing halftones in Illustrator.
This is a great tutorial. Thanks for sharing this @Christopher
Ditto 
Thanks😉
I’m really going to have to look into getting illustrator
Don’t know if you are Windows or Mac, but consider checking out Affinity Design. There are several of us on here who have purchased it and it’s apparently very competitive with Illustrator. The Windows version just came out, I think. I’m on Mac and It is a really fantastic app and best of all, no subscription fees…just a flat out purchase. Don’t know the current cost, but I think I paid only about $50 for it.
I have both Designer and Photo on my Mac. $49 each, but I found iTunes gift cards on sale, so gave myself a 15% discount.
I’m on windows. I will have to check into that. I don"t like the idea of a monthly payment to use illustrator.
I purchased the Affinity and the textbook (recieved that today). Unfortunately the affinity won’t install on my desktop ( some windows missing error…) so I’ll have to try on my “newer” laptop - which I use with my silhouette and probably with my GF on my crafting table. Anyone using this software yet - I’ll start looking through the book this weekend I imagine.
WOW!!! I so want to try when I get my glowforge. Thanks for sharing!
It’s on sale now for $39.99 if anyone is interested. I started watching tutorials to see if it’s something I can use. It has similar features to both GIMP an inkscape.
My mind is officially blown. 
WWWWOOOWW!!! Bookmarked!!