single piece iron dyed zipper card casethe card case has been hand cut from a butter soft full grain washed and tumbled 1. 3mm vegetable tanned natural horse culatta leather with an iron dyed finish that has been brewed in the atelier for 18 months and offers an array of grey nuances. culatta is a special cut combined of the rear just above the cordovan, the belly middles and the hind shanks, offering a dense structure, tight grain and medium to firm temper. vegetable tanning is a