The preservation of graptolites as pale films is characteristic of many low grade metamorphic lower Paleozoic rocks. A study of such fossils at Abereiddy Bay, South Wales allows an interpretation of the abundant graptolite fauna under varying conditions of bedding-cleavage relationship. Similar phenomena are also documented from other localities. The bulk of the pale «fossil» seen in many of these situations is a tectonically induced silicate pressure shadow with the broken, frequently partly pyritized graptolite concealed inside. Clearly the dimesnions of such fossils will not accurately reflect the original form of the rhabdosome. This has significant implications for their use in structural and taxonomic analysis