The effect of the amount and type of latex on the mechanical properties of the paper‐polymer combinations is described in detail. The treatment with latex increases the wet and dry strength properties of the paper considerably, together with improving the folding and tearing resistance. If the polymer in latex is below its film‐forming temperature, however, the beneficial effects of latex treatment are absent. Limitations to varying the rheological properties of plasticpaper combinations are imposed by the comparatively inextensible nature of the paper matrix. Methods of improving the extensibility of paper, including the use of synthetic fiber papers, are discussed, and the time‐dependent nature of the properties are outlined.