The replication of technique in copper production includes a vast number of possibilities in trying to recreate what has been found through archaeological excavation. Tylecote and Boydell have experimented on possible explanations for the levels of iron found in certain copper objects and the possibility of removing excess iron through the re-melting of the copper. Crew has also done experimental work on iron to show possible loss in iron mass due to the processes involved with working the metal from bloom to billet which concluded with a loss of 75% in slag, impurities, and iron metal.