I don't believe there are any rules covering your overlay process. You would follow Formats rules for the text. Here are a couple of suggestions for creating overlays. Stagger the location on the pages so that all of the plastic is not at the same level on every page. Round off the corners of each plastic application. Rounded corners make it more difficult to peel the plastic off the page. Very important -- proofread carefully before actually sticking it on the page.