Tanned hide: Pure in the Hanafi principle subject to the pig and human exceptions; dog hide is disputed with the Shafi‘i school.
Carrion hair: Pure with qualifications in the Hanafi view, impure in the Shafi‘i view, pure in the Maliki view.
Carrion bone: Pure in the Hanafi view, impure in the Shafi‘i and Maliki views.
These positions rest on different understandings of the substance, the effect of tanning and whether death transfers impurity to a particular part.