- GeoRef, Copyright 2004, American Geological Institute. Reference includes data from Bibliography and Index of Geology Exclusive of North America, Geological Society of America, Boulder, CO, United States
Discusses the technique and the conditions for giving the best results. Concludes that rubber latex is best for making impressions from casts in sandstone while phenol formaldehyde plastic is better for soft argillaceous sediments. Latex does not penetrate the rock so much as phenol formaldehyde plastic and can be pulled away from the cast. In the use of the latter the cast is destroyed.