Alum Backs and Riempies
This is a special tannage that is primarily used in the furniture business where the white alum backs are cut into strips of ± 1.6 – 1.8 meters in length, known as Riempies. These thin lace like strips are used in chairs as a cushion base. Only available in white. Substance range: 3.5 – 4 mm.
Alum tanned leather is transformed using aluminium salts mixed with a variety of binders and protein sources. Alum-tanned leather is technically not tanned, as tannic acid is not used, and the resulting material reverts to rawhide if soaked in water long enough to remove the alum salts. Alum backs are cut into strips for riempies.
Rawhide is made by scraping the skin thin, soaking it in lime, and then stretching it while it dries. Like alum-tanning, rawhide is not technically “leather”, but is usually lumped in with the other forms. Rawhide is stiffer and more brittle than other forms of leather; it is primarily found in uses such as drum heads and parchment where it does not need to flex significantly; it is also cut up into cords for use in lacing or stitching, and for making many varieties of dog chews.