Most high-grade glue is made from pure bovine hides. The glue is manufactured from the protein collagen found in skin, connective tissue and bones of animals.
Like rabbit skin glue, bovine hide glue provides a low cost, easily formulated paint that is called distemper. Diluted with water, it is good for color sketching, as well as for painting. Distemper paintings have lasted for centuries without change.
Rabbit skin glue is much stronger than most hide glue and also has a greater expansion rate when water is introduced prior to cooking.
The following hide glue specifications are from the product sold by Natural Pigments: “Hide glue is graded and sold by its Bloom Value. Bloom value is a measurement of the strength of a gel formed by a 6 and 2/3% solution of the glue that has been kept in a constant temperature bath at 10� C for 18 hours. A device called a Texture Analyzer is then used to measure the weight in grams required to depress a standard plunger 4 millimeters into the gel. If this procedure requires 200 grams, then the glue is a 200-bloom value glue. Glue is also tested for its viscosity at this same 6 and 2/3% concentration. A standard viscosity range is associated with each bloom level. Its low bloom value gives it a longer setting time, making it ideal for use in gesso and for sizes (the bloom value refers to the strength of a gel formed by a 6 and 2/3% solution of the glue kept at a constant temperature- the higher the number the greater the strength of the glue).
Hide Glue Recipe:
The standard recipe is one part glue to ten parts water. First soak the granules in water for 30 minutes and then heat gently in a water bath until completely dissolved (for about 30 minutes to one hour – allowing it to bloom). Warm this swollen glue by placing the container in another vessel filled with hot tap water. This will cause the glue to completely dissolve. Never heat collagen glue over 140 F.
Here is the link for the text in it’s entirety http://www.naturalpigments.com/hide-glue.htm
Double boiler for glue, water and granulated hide glue
Once granules lave liquified.
A chart that I stumbled across online that places glue within a context of other binders for woodworking.
A great material context and summary for hide glue.
