I've used transparencies for printmaking. -- Stencils and mono-prints.---Roll
ink onto the surface of the plastic, write in the ink, roll another color on top
, print onto the surface of the plastic and transfer it to paper. Experiment.
Also---just paint on the surface and print the painting.
I just had a parent donate a box of colored overhead transparencies to
my class for 'art projects' (I teach 2nd grade). Any ideas? One of my
colleagues suggested window art with our science theme (we are in
dinosaurs right now).