I suppose as long as you are not putting the item in the wash it should work. I have used that iridescent packing material instead of mylar. .I also used bits of mettalic threads and yarn because I felt that the digitizing is as such to let material show through yet keep it in place. Have fun

What ever it is it is very pretty for your project it but definitely is NOT mylar. Mylar is the brand name for a special type of stretched polyester film and is not the stuff used for embroidery.