The Roman Bun Ingots are less pure than the earlier LBA examples and Tylecote suggests that they may be a direct product of smelting. Theoretically such an ingot could be formed in the base of the furnace. However, this is problematic in the case of the stamped examples as this would require the furnace to be dismantled or else have a short shaft to allow access for stamping. As a solution the furnace could have been tapped into a mould at the completion of smelting. It is possible that both methods were used as several of the ingots seem to have had additional metal poured onto the top in order to allow stamping.