Vintage cotton 'flour sack' from Diamond Crystal Salt, 100 pounds size (about 34" long x 17 1/2" wide, still sewn up as a bag).
This has great printed lettering, nice and black without fading. But this does have some discoloration and spotting, though no rips or holes.
It might clean up with a soak, but I haven't tried it since I didn't want the printing to fade!