Sounds like people do use inkjet transparencies for their “positives.” I work with wide format printers and I want to use them to make oversized screens. I have access to vellum, film, and mylar and we have an inkjet printer that we use for color jobs but mostly we use toner printers. I like to use toner because it’s so fast. The inkjet can take hours to lay down what the toner based lay down in seconds. Will toner stop the light? I was going to try vellum first. Or maybe double up two film prints(film is the only one that’s actually clear but doesn’t always get solid print) What’d ya say?