What is glue?
Glue is a sticky all-natural product created by boiling parts of animals to make a brown, translucent, and viscous substance. Protein colloids is extracted from the skin and bones of animals through a boiling process that causes hydrolysis to the collagen. Rabbit-skin glue and Russian Sturgeon glue (Isinglass) is still used today by paintings conservators and gilders.
Mucilage, created by plants, can also be boiled to create a sticky product. Mucilage is used by plants to assist with the storage of water and food, seed germination and to thicken cell membranes.
How do you know if glue is on your record?
The presence of glue exhibits physical traits such as penetrating through paper. It is inflexible, hard, and shiny, with a brown tint. Typically it is found on items from the 1800s – 1950s, though it is still available today for purchase at art and hardware stores. Glue is often found on envelopes, framed items, and scrapbooks from 1950 and earlier.
What is adhesive?
Adhesive is a synthetic product. There are many different types, some of which include thermoset adhesives, thermoplastic adhesives, and pressure-sensitive adhesives, though there are many others. Not all adhesives are made equal. Some are chemically and physically stable, while others degrade quickly. When adhesives degrade they first become sticky and gooey, then they begin to lose their adhesive properties and harden, finally they harden completely and the paper will often detach.
How do you know if adhesive is on your record?
If the record has pressure sensitive tape, is framed or matted, and is from 1960 or later, it is likely that there is adhesive present. Adhesive is hard and shiny, can cause yellow or brown staining, and may cause the paper to appear translucent. Many adhesives cause paper fibres to weaken leading to tearing and loss of media. It is recommended to have a paper conservator treat the item to remove as much adhesive as possible, and to improve the stability and aesthetic of the record.