The bottom line is COTTON ROTS, everything seems to weaken cotton material, sunlight, chemicals, both in detergents, and even unknowns in your super whiz patchlube. So using recycled denim is just asking for trouble. If I have to use a denim type material for patching, I prefer pocket drill. Look at the ragged pair of jeans you were cutting your patches from. Now look at the front pocket where you carry your keys, there’s a good chance that even though the jeans are in rags the pockets are still good. That’s tightly woven material, and thats what you want for patching.
Hungry Horse