The marks used by Mason were principally the following:
MASON’S PATENT IRONSTONE CHINA
MASON’S PATENT IRONSTONE CHINA.
MASON’S PATENT IRONSTONE CHINA ASHWORTHS.
MASON’S PATENT IRONSTONE CHINA.
PATENT·IRONSTONE·CHINA
Figs. 479 to 483.
Figs. [479 to 481] are printed, usually in blue, on the bottoms of the pieces, and Figs. [482 and 483], impressed in the body of the ware.
After the patent passed out of Mason’s hands into those of Morley and Co., the mark was changed on more than one occasion. The principal one was