A short video of the testing process on my salmon parchment conducted recently by Tim Barrett at the University of Iowa Center for the Book Research and Production Paper Facility.
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."
TESTING REPORT
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. 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 test results:
Material
Test
Tests
Final Averages
Fish Parchment
Fold
2
79,338 folds
Tear
3, Disqualified
NA (Did not tear across full width due to strength)
Goat Parchment
Fold
2
12,015 folds
Tear
6
784 gr/cm
UICB Flax Papercase Paper,
circa 1992
Fold
60
4501 folds[1]
Tear
60
828 gr/cm[2]
[1] Average from test strips cut in both the chainline and the cross-chainline directions.
[2] Average from test strips cut in both the chainline and the cross-chainline directions.
Used my last piece of salmon parchment to have it tested for fold and tear strength, so had to make a new one. Note the translucency! So glad Wegman's has salmon fillets in a family size. Good to have Fritz Otto around to hold it up for photography...
Very glad to have had @bookbinderbarbie visit this summer – THE highlight in my studio.
Don't stop learning and binding, and keep in touch.
Honored to have won "Most bookbindery photo?" The NBSS knit hat will keep me toasty during our brutal Syracuse winters and in the slightly warmer studio.
