The technique is suitable for strong and durable objects because it does not compromise the structural integrity of the metal. Between 1500 and 1750, production centred on southern Germany and northern Italy where etched armour was a speciality. Daniel Hopfer of Augsburg, a renowned etcher of armour, is widely thought to have invented etched metal plates for printing on paper. Printed etchings are often freer and less exact than traditional engravings, capturing the ‘hand’ of the etcher rather like a pencil sketch.