Even the back of a mask can look cute. I printed this cat silhouette, which I found on the internet, I haste to say, on plain A4 paper. I was concerned it might be too flimsy to act as a mask, but far from it. I've actually used some of them twice already and they've kept their shape and structural integrity. So much so that I think they will improve over time, with more and more layers of acrylic paint.