It’s simple, if the adhesive comes in direct or very close contact with artwork, you should avoid using a self adhesive product whenever possible.
We get this question a lot! What’s the right product, tape, adhesive to use? There are MANY choices. Our goal with this post is not to give specific advice but to help understand the general differences between product groups to help determine what products may be appropriate for different applications.
In this post we will cover different adhesives commonly found on tapes used in the archival market.
Water Activated Tape or WAT or Gummed as it is sometimes described in the industry is made from starch. Starch is considered a very stable adhesive and is used commonly by conservators. Starch will easily swell (moisten) with the introduction of water, which is how these tapes are activated. They can also be removed through a similar introduction of water or steam. The bond generated to porous materials such as paper and board with these adhesives is excellent and very long lasting. We’re talking 100+ years! Here at TALAS, in addition to gummed tapes, we sell a variety of starches used for adhesive, and one can easily coat their own paper to make a re-moistenable tape.
Some examples of these types of tapes would be our Heritage Gummed Paper Tape, or Gummed Cambric Tape. Alternatively, examples of starch adhesives would be Wheat Paste or Methyl Cellulose.
Self Adhesive Tapes, also referred to as Pressure Sensitive Adhesives (PSA) or just even Tape is a type of adhesive which is basically peel and stick. It requires no drying, curing, or anything else other than pressure onto a surface to work. There is no wondering why they have become wildly popular. Unfortunately though we’ve all seen these adhesives after time when they become yellow, dry, and crumbly, and the staining they can leave behind. These products have improved, and there are some of good quality out there. Gudy 870 and Gudy 831 are two such tapes that have both passed the Photo Activity Test (ISO 18916) which is an accelerated aging test. However the long term stability of this type of adhesive is always suspect. It can be very difficult, if not impossible to remove, and once it has deteriorated it becomes very detrimental to what it is in contact with. In any case, self adhesive tapes generate very good bonds with non-porous materials such glass, plastic, metals, etc which are materials that gummed adhesives generally do not.
In summary, PSA adhesives have a time and place in the archival world but if at all possible they should not be used in direct contact with original artwork. Gummed adhesives are excellent, but do not work for everything.
As always, we are here to answer any other specific questions you may have!
