The Department of Invertebrate Zoology (IZ) at Harvard University’s Museum of Comparative Zoology (MCZ) houses specimens that are both fluid and dry preserved. The holdings today represent well over one million specimens within approximately 350,000 lots, nearly 8,000 primary types, plus several thousand secondary types. Historically, in IZ, various types of paper data labels have been used inside the jars of fluid preserved specimens. The materials used for these labels range from cotton paper to acid-free paper where India ink and pencil are used for writing. Any label submerged in a liquid over time would be expected to deteriorate moderately. However, in a museum setting, where the preservation of a specimen’s original data is found on those labels, the stability of the selected label type is paramount. Currently, the IZ and several other departments in the MCZ utilize thermal printed labels (Datamax-O’Niel I-4380) for fluid preserved specimens. These printers use plastic rectangular labels which are heated and ink is “burned” into the label itself. This process helps prevent fading, and bleeding of ink over time. Many specimens have both thermal as well as historical labels of varying paper types in their jar. Thermal labels are often also used when a specimen is in the process of being “stained” for CT scanning since the plastic label does not absorb dark ink such as Iodine. However, it was observed that the addition of these stains led to the complete loss of legible data on the thermal labels. The text on these labels became virtually unreadable when the labels were exposed to iodine or bleach. Researchers at other institutions should be mindful of their particular treatment of labels. Additional steps should be taken (i.e. keep copies of labels on the outside of specimen jar) when putting specimens into contrast stains (i.e. iodine), to avoid the loss of specimen/collection data before non-destructive imaging techniques are used.

Datamax, Thermal Labels, Iodine, Bleach, Plastic Labels, Preservation, India Ink

Jennifer Winifred Trimble