Sau los ntawm epinatural leatherl hlwb nrog ntau hom, cov kab mob qhov chaw nyob hauv cov plaub mos mos, tuav tawv nqaij. Hom tsiaj sib txawv nyias muaj nyias qhov txawv ntawm leatherl thickness. Piv txwv li, cov tawv nqaij ntawm cov quav nyom yog 0.5% los ntawm 1.5% ntawm nws cov thickness, thaum yaj thiab tshis nkaum 2% rau 3%, thiab npua nkaum 2% rau 5%. Lub cev tawv nqaij, nrhiav hauv qab kabmob (epidermis), nruab nrab ntawm cov kabmob epidermis thiab, yog qhov tseem ceeb ntawm cov nqaij npua. Qhov nyhav thiab qhov nyhav rau 90% ntawm cov nqaij nyoos.
Feem ntau peb xaiv qhov tawv nqaij uas muaj tawv nqaij 1-2 hli los ua cov txiv neej lub hnab tawv me, daim hnab khi, daim tawv ceev, daim nplaub tshev, daim tawv nqaij thiab lwm yam. Yog tias tawv tawv heev dhau thaum ua daim ntawv xov xwm tawv lossis lub koom haum, nws yuav shoveled ua ntej ntau lawm los ua kom nws ntau dua fittable.