So, how did the tests go? Douglas Adams, author of The Hitchhiker's Guide to the Bookbinding Materials wrote, "salmon skin is strong. You just won't believe how vastly, hugely, mind-bogglingly strong it is."
University of Iowa Center for the Book
Research and Production Paper Facility
October 17, 2019
P. Verheyen provided samples of goat skin parchment and fish skin parchment, both of about the same thickness. An MIT Folding Endurance tester and an Elmendorf Tear tester were used to gather the reported data, although both are designed for evaluating the mechanical properties of paper, not parchment. The two related TAPPI standard procedures used were T 511 and T 414.1
The following important exceptions to the specified steps occurred during the tests:
- None of the specimens were pre-conditioned or conditioned nor was testing done in a temperature and humidity controlled room. RH varied between 30 and 42%.
- Only two strips of both parchments were subjected to fold tests and 13mm wide strips were tested rather than the specified 15mm wide strips.
- One ply of each parchment was used for the tear testing.
- Three fish skin parchment tear tests were attempted and all were disqualified because the required tears across the full width of the specimen were not possible due to the strength of the material.
Below the results for goat parchment and PC4.