Purposefully purple: understanding the technological transition from late Medieval green to purple glazed Humber wares

The rise of purple glazed pottery in fifteenth-century England represented a major change in the character of domestic material culture. These wares typically evolved from the orange bodied, green glazed pottery of the later medieval period and were produced by a number of centres. This paper examines the technological advancements made by potters working at West Cowick (East Yorkshire) as they navigated the transition from green to purple glazed Humber wares. While it well known that recipes and firing regimes can be manipulated by potters to modify and enhance their colour pallet, the change exacted by West Cowick’s potters has been overlooked, dismissed by archaeologists as the result of over-firing. Through a range of analytical techniques (thin section petrology, scanning electron microscopy microstructural analysis, chemical characterisation of fabric and glaze by portable X-ray fluorescence analysis and scanning electron microscope–energy dispersive spectroscopy), we reconstruct the glazing practices employed by these potters, revealing innovative artisans, skilled in controlling glaze recipes and firing regimes, and able to effect major intentional changes in their product.