The skill reqs are fubar on the Hide Strip entries for the T1 and T2 recipes of these formulae.
Rough Leather Cap/Mask is carrying the skill reqs of Hardened Leather for the Hide Strips (520/560). Should be 120/160.
Tanned Leather Cap/Mask is carrying the skill reqs of Reinforced Leather for Hide Strips (720/760). Should be 320/360.