Stencil RevolutionButterfly - Reusable s for Painting - Mylar for Crafts and Decorations

Can this be used for watercolor painting?

I want to use this in watercolor, by stenciling the paper first. can this be done? when i hear of mylar, i think of flimsy balloons, is this flimsy?

Can you use etch cream to etch this design on glass?

Do you have smaller than 5 by 6 like 3 by 4 ?? I need smaller size