Thanks for stopping in, Spiros (@fiveten), John (@johnb), and Paul (@yellow10). The stuff I used to make the masks is a stencil material that is designed for the Cricut Joy, but it is similar to the other removable stencil material used by the craft cutters used in card making and other hobbies that require a stencil. It is a 2-part material that has the flexible stencil vinyl layered on some sort of thin backing, usually paper, but thin plastic in the stuff for the Joy. Once you design what you want to create, you can send it to the machine and it cuts it out for you. In the cutting process, it cuts the design into the thin, flexible material on top, but leaves the backing material intact. then you simply peel off the masking material and place it where you want it. It is self-adhesive but removable. It has about the same stickiness as masking tape. The Cricut Joy is a relatively new machine which is much smaller than Cindy's other machines. When I get a chance I will take some photos of the machine and the stencil material so you can see what it looks like. I am just starting to learn enough to make the machine useful for my modeling.
Thanks for the kind words, Paul (@yellow10). I think you are looking at the old teacher coming out in me. I taught high school and college history for 20 years, so I enjoy the research. I tend to over-share about modeling steps and techniques, but once again, old teacher coming out. Glad you stopped by.