It's a well known issues for art journalers, like myself, who work with heavy body acrylic paints- liquitex and golden that they stick to the previous page if there is one ounce of acrylic on it. And forget it if you apply heat. The pages are done. Samantha gives some good tips. I've got a few of my own. First If you work in acrylic go over the page with watercolor crayons, a think layer spread out with water on a brush helps to keep the pages from sticking. As will a layer of nupastels, artstix or colored pencil. In the art journal I did previous to the current journal I used layers of a 50/50 mix of bee's wax and parafin. I made a palm sized cake of it and would rub it over the top of my dried pages. After that I would buff it into the page with a rag. If I wanted a really heavy layer of the wax I'd heat the page with my heat gun and rub it onto the warmed page, then I'd heat it again and buff. I get very little sticking in that journal and I worked some pages very impasto.