Hello Inspire - I`ve not tried painting on acetate but I would think it would be necessary to abrade the surface slightly to get the paint to adhere. I would look on the internet for a supply of acetate sheets. Good luck!
Anne Smart PA/RSC Peterborough

Hello, just found this post.
I have been doing a bit of painting on acetate sheets lately, black acrylic gesso takes well without having to do any preparation, then I scrape off areas (scraperboard style) and repaint coloured acrylic over the the top. Looks very effective when you flip it over to view from the non-painted side.