Science education researchers have turned their attention to the use of images in textbooks, both because pages are heavily illustrated and because visual literacy is an important aptitude for science students. Text-image integration in the textbook is described here as composition schemes in increasing degrees of integration: prose primary (PP), prose subsumed (PS), and fully integrated (FI). These schemes enable experimental research with authentic media without diminishing complexity. Seventh grade subjects used media variants in a within-subjects design (N = 158). Comprehension tests revealed higher comprehension for FI over PP media variants in one of three sessions (P = 0.0073). FI scores were highest for the other tests but not significantly so (P>0.05). A post-test situational interest measure revealed a significant preference pattern of FI>PS>PP. As textbooks follow a general PP strategy, expansion and confirmation of the results would suggest increasing the degree of text--image integration for middle school science textbooks.