Post ID: 6753

conservethis:

What tape does to paper. You can see my fingers through the tape, which has made the paper translucent.

Here’s a bit more of an explanation about what’s happening between the tape and the paper in the photos above:

“A good example to illustrate examination and treatment methods is an artwork on paper onto which a rubber based cellophane tape has been applied. A classification system is used to determine the degree of degradation of the tape, a factor that is critical to planning the removal strategy. In stage one, called the induction stage, the tape seems healthy. The adhesive is functioning well, the carrier is stable, and no discoloration is apparent. In stage two, called the oxidative stage, the carrier is still present, but the adhesive is stringy and overly sticky. During this stage volatiles such as plasticizers are lost, and the
rubber elastomer is actively oxidizing. The tape may be discolored from the cumulative effect of a number of chemical changes. In stage three, called the crosslinked stage, the adhesive has failed, and the carrier is gone or will come off easily. The adhesive is brittle, highly discolored, and the paper to which it is affixed is translucent from penetration of the adhesive. After the stage of deterioration is determined, other observations are made, such as whether there is plasticizer migration or dimensional change in the carrier. Microscopic examination can show if underlying media have been affected, and crossed polar viewing can help determine the carrier material.”
-Quoted from “Pressure sensitive tapes and our cultural heritage” by Elissa M. O’Loughlin, Associate Conservator, The Walters Art Museum, Baltimore, MD