Watermarks such as John Allen Superfine, John Allen Fine, Ermevale Superfine, Ivy-Glen Linen and Old Plymouth 191 Bond were all discontinued when Portals, the renowned manufacturer of banknotes, acquired Stowford Paper Mill in 1924.
Portals were at the time extending their business activities, having secured contracts for the supply of postal order paper in 1881 and pension book paper in 1908. Additional manufacturing capacity was needed and Stowford Mill was ideal for their expansion plans. Upon acquisition in 1924, a subsidiary company was formed under the title of Portals (John Allen & Sons) Limited.
Other watermarks such as John Allen & Sons Extra Strong, Eddystone Loan, Ivybridge Linen, Ivybridge Bond and Commander were however, retained. Commander was transferred to Turkey Mill in Keighley, another mill Portals had recently acquired. Portals however introduced new watermarked grades to Ivybridge such as Wykeham Bond, Wove and Laid (first made in 1924 but later discontinued in 1939/1940), Economy Bond (first made in 1928 and discontinued in 1940), 1927 Extra Strong Wove and Laid (first made in 1927 and discontinued in 1933) and Ivybridge Blotting (made between 1927 and 1929).