Throughout the history of Portals Mills their commercial success has been based on their ability to incorporate watermarks in paper used for banknotes. Watermarks make it more difficult for the banknotes to be forged, a technology which is also used in paper for other documents. Jack Sheldon worked for Portals for many years as an artist designing watermarks and we have recently been most fortunate in being shown his portfolio which includes some work from other mills in the Portals group. Cont…