1/4 pound (4oz) of 251 gram strength granulated hide glue, regular clarity. Hide glue has been used for thousands of years and is excellent for gluing felt, wood, leather, cork, cardboard, paper and for player piano work, luthier work, cabinet work and much more. Great glue, strong and can be separated later as needed (unlike many modern glues). Use with a glue pot or double boiler setup at 140 degrees Fahrenheit. DON'T use the small glue pots made for hot glue chips as they get too hot. If you exceed 150+ degrees Fahrenheit for more than a few minutes it alters the protein chains in the glue and significantly weakens the bond. Dry glue crystals can be stored a very long time if kept dry. Glue mixed with water should be kept in the refrigerator when not in use. If you notice mold or white spots forming in the glue, discard and mix a fresh batch. Gluing some test pieces of wood and deliberately breaking the joint is a good way to see if the working time and strength of hide glue is sufficient for your needs. Lets discuss gram strength (the number of grams required to depress a 1/2 plunger 4mm into a quantity of glue that has been mixed to a 12.5% solution and cooled to 10 degrees celsius for 16 hours): gram strength does not necessarily refer to the strength of the bond (though there are subtle differences) but rather the set time of the glue. A 192 strength glue will have a longer working time than a 251 - the lower the number, the longer the working time. Regular versus high clarity: if using in an application where minimal visibility of glue joints is desired (cabinet, carcase, guitar/violin or other musical instrument bodies) we recommend high clarity as it has less visible glue lines. For applications where visibility isnt an issue, regular clarity is fine. Ragland Piano hide glue comes with a silica gel pack, to absorb moisture and help extend the life of the glue.