Operations such as surface dyeing, buffing, embossing, lacquering, plating, or applying a finish coat constitute 'further preparation' that takes the leather beyond the crust stage. A hide that has only been tanned and dried without any of these additional steps remains in heading 4104, while one that has been finished for direct use in manufacturing articles belongs in 4107.

A whole hide is the full skin of one animal, while a side is a longitudinal half of a whole hide — a standard commercial cut. The tariff schedule places whole hides under 410711–410719 and sides (along with other non-whole presentations) under 410791–410799. A half-hide (side) therefore falls in the 410791–410799 group, not the whole-hide subheadings.