Labels for Eternity: Testing Printed Labels for use in Wet Collections

Will printed labels survive prolonged immersion in collection fluids, and, if so, which printing system is preferable: inkjet, laser, or thermal transfer printing? In a world with a wide variety of printers, printing substrates, and printer technologies, the interactions between them very likely affect long-term label preservation in the chemical environment of the preservation fluid. In fluid-preserved collections, the main issues frequently encountered with labels include delamination, abrasion, fading, and disintegration during immersion in solutions such as ethanol and formaldehyde aqueous solution (widely known under the commercial name formalin). Very few publications have presented testing procedures assessing the behavior and stability of printed matter immersed in the types of solvents used in fluid-based collections. This article presents a series of experiments set up at the National Natural History Collections at the Hebrew University of Jerusalem to test a variety of museum labels. The tests compared labels actually used in different natural history collections and included labels from both thermal transfer and inkjet printers. All were subjected to accelerated aging and mechanical abrasion. In our series of tests, inkjet labels gave the best performance.