Qirṭās means paper, whose smooth, clean surface is the point of comparison. Mishfar is an animal’s lip. Sibt refers to prepared, supple leather; al-Yamānī associates the leather with Yemen.
Qadduhu draws attention to the way a strip is cut. In this context lam yujarrad contrasts the lip’s even line with a cut that is irregular or marred. The focus is on form and workmanship, not on an actual leather strip attached to the animal.