Hide glue from the hardware store has a definite shelf life. The date used to be stamped on the back of brown plastic bottle, in tiny white illegible numbers. The reason for this dating was that the urea -- used to keep the glue from just re-linking it's molecular strands of protein chains back into a semisolid in the bottle -- also eventually will destroy the ability of the chains to link at all. Think: 'Velcro' with limp hooks and eyes. AND -- when the protein and water mix starts to "go off", it definitely will be odorous, as well as thin and runny.
However, the current mix in the brown plastic bottle in the paint section seems to have a longer shelf life. As well, I use them rather quickly, anyway. It is quite useful in the restoration biz, including as an adhesive for putting down pool table felt in cases, traveling desks, and tables. As well, it is well suited to tedious wood repairs, due to it's long open time AND the fact that it can be undone, in the case of a clamp slippage or my own miscalculation of something.
Depending on what application is being undertaken, one can also choose from several strength grades of granular hide glue, which is warmed with water to no more than F 135 degrees. Going higher tends to cook the protein, lessening it's strength. The highest 'gram strength' grades were actually painted on plate glass in decorative patterns, where the strength of their adhesion when curing would cause glass chips to spall out the surface, creating twining vines with leaves, or other motifs.
Like the use any material, a good deal of reading about it's use, the patience to try and fail until successful, and the ability to learn from and to fix one's mistakes are helpful to the would-be craftsman. Hide glue is nice about that process, being easy to try, try, try again. Cleans up nicely with warm water or a bit of white vinegar, BTW. And it's a damn good glue, too.
Now: comes now the fly in the olde-tyme pantry for reciepts to the laying of baize, felt, leather and the like. The traditional material was and is wheat paste, and a good one it is, tho tedious somewhat in it's proper preparation. Soooo .... you must now pay me five hundred dollars, for my weekend course in the use of modern materials in lieu of the sticky old stuff.
Or you can just read this paragraph for free, I suppose: vinyl wallpaper paste will do all the needed stuff for the cloth[s] under discussion, nicely. It doesn't go all mouldy like wheat paste, nor does it require an interest in fundamental traditional woodworking materials and their uses, nor do you have to use materials that cannot be 'undone'.
The small family shop that puts down VERY expensive leather tops on fine furniture for Sotheby's in NYC uses ordinary, over the counter, vinyl wallpaper paste in a plastic bucket. It spreads easily, has a long open time, allows repositioning of boo-boo's, cleanup is plain water, the nap of the cloth can brushed out, and it is cheap.
The stuff is handy, cheap, and does the job as well as the most complicated or toxic or insoluble adesive. It actually is easier to work worth than any of them. Commercial liquid hide glue as describe in other posts above, is the second choice, and it's adhesion is much stronger, for applications where the cloth is constantly being stressed, subjected to sheer pressures, or being shoved about in some manner.
Hide glue on one's fingers and using the keys on a computer keyboard are not a compatible activity, BTW, should you keep a 'puter in the shop.
Adidas,