Glue from Fish?

I do not remember what I was watching the other day when one of the characters made comment about fish glue being used as an adhesive before the current type of adhesive.

My ears perked up because I was unaware that anyone had ever used fish to make a glue.  Fish glue is also known as isinglass.  It is a transparent, water soluble glue made from different varieties of fish.  For a while, the best grade of fish glue was made from the Beluga Sturgeon but due to over fishing, they had to quit doing that.

Fish glue is quite sensitive to humidity and temperature changes and often shrinks as it dries.  It does not dry quickly so you have time to get it applied properly but you must clean any brushes up when the glue is still damp otherwise it is difficult to remove.  Fish glue can be cooled but it cannot be frozen or it becomes useless.

There are references to using fish glue as far back as about 3500 years ago in Egypt but it appears the quality varied according to how it was produced. There are even references of fish glue being used in Ancient China.  Flash forward to an eighth century manuscript which makes reference to fish glue being a material they painted on.  Fish glue is again mentioned in a twelfth century manuscript where the author mentions mixing ground up gold mixed with fish glue so manuscripts could be gilded.

Around 1390, the first comments appear on how great fish glue is for fixing lutes, fine paper, or objects made of wood or bone.  During Medieval times, they wrote on parchment that was frequently reused.  To make it reusable, parchment had to be sized and one way of sizing it, was to use fish glue. In addition, the fish glue was used to repair damaged parchment.

Several artists discovered that fish glue could not be used alone in the seventeenth century or the final product became extremely brittle.  This lead to the use of a "plasticizer" such as honey or molasses when restoring earlier art works containing fish glue.

In the nineteenth century, artists developed a new technique where they coated paintings with fish glue mixed with gouache to create the same shine as oil paint.  Unfortunately, the paintings began cracking over time.  Furthermore, another artist created a technique where they applied water color to a specially prepared Bristol board so it was finished with a solution containing fish glue before a final layer or regular varnish.

Artists tried mixing fish glue with pastels and other materials to create new looks, new uses, and the perfect media. As you can see, fish glue has a long history of being used as an artistic media rather than just a material to stick two things together like Elmer's.  I'd never heard of it till this reference and its interesting to discover more about it.  Let me know what you think, I'd love to hear.  Have a great day.