We propose to study 25 English Medieval Brass Letters from the collection of the London museum and the Oxford Museum. We would like to determine the the alloy composition of these Brass Letters. We try to build up a full picture of the recorded Brass Letters in UK collections with the intend to deduce workshop practise and individual workshops during the period 1250 -1400 AD. We intend to use the NRCA option of the INES set up to look for traces of fire guilding.