Hardtack appeared in different national forms. Alex Clarke found the Japanese hardtack he tried just as dry as other ship's biscuit. A British Arctic expedition took hexagonal pieces because the shape was supposed to make them easier to store. A Danish example apparently survives from 1852.
Notable Point · 5:14-6:23
Hardtack shapes, storage, and surviving examples
Japanese hardtack, hexagonal Arctic expedition biscuit, and a Danish survivor illustrate the forms and durability of ship's biscuit.