A blog by Emily Forster, Archivist.
Sellotape is one of the great modern inventions, making repairs of torn paper-based items quick, clean, and easy. However, to the archivist and conservator, it sends shivers down our spines, and we know there will be a lot of work to do on the affected document.
Sellotape in its advanced stages, with staining on the record
Why is this?
Sellotape, or pressure-sensitive adhesive tape, is generally made up of two layers, the top non-sticky bit, which is usually a clear film, and the bottom layer, which is traditionally a rubber-based adhesive, and is the sticky pressure-sensitive adhesive. This adhesive for pressure-sensitive tape degrades paper, and often leaves the paper discoloured.
In addition, Sellotape was never meant to be used in the long-term; it is only a short-term fix. The top layer degrades becoming brittle and shrinks, in many cases it can be manually removed, undoing the repair in the process. Pressure-sensitive tape is not the first port of call if you want the document you are repairing to last a long time.
Volume with Sellotape
Top layer removed, sticky residue left behind
What do we do about it?
It is best to get the tape off as soon as possible while the tape is ‘fresh’, using techniques taught and supervised by a trained conservator.
If the tape has been on a document for a long time, it may have lost its stickiness, and the film top layer may be brittle. In this case, it is sometimes possible to gently lift the top layer away, leaving the solidified adhesive on the document. It may be possible to reduce the hardened adhesive with a scalpel if the document is not placed in danger from this process.
Further example of Sellotape staining
If the tape has been on the document for a shorter period, it is likely the film layer will still be intact, and the adhesive layer will still be tacky. In this instance, the conservator will use gentle heat to reactivate the adhesive to facilitate the removal of the tape without further damage to the document. The tacky adhesive left behind on the paper is removed with a special crepe eraser. If the residue is particularly sticky, it can be dusted with wheat-starch powder to reduce the stickiness and allow for safe removal with the crepe eraser.
If you have any questions about conserving paper-based records, contact us! Our conservation team will be happy to give advice.
Wheat starch powder being added to the tacky layer
Special crepe eraser to remove the tacky layer
And it’s not just pressure sensitive tape found on records!
Our conversation team have found lots of different tapes on all kinds of records, like gaffer tape found on a bible, and electricians tape found on various other documents. Sellotape is also more often found on records dating from the 20th Century; it is rarely found on older records, such as from the medieval period.
Sellotape and tacky layer fully removed from right side
Everything that was removed from two pages
Should I throw away my Sellotape?
Definitely not. How would you wrap up presents? Maybe with rubber bands… which is another issue conservators have to deal with!