iron culatta leather hybrid backpackthe versatile bag has been hand cut from a butter soft full grain 3. 5mm vegetable tanned, washed and tumbled natural horse culatta leather with a visible layer of subdermal cordovan. 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 traditional method of treating the hide using natural extracts such as