This early 19th C Mason's 8" plate is decorated in the hard- to- find Japan Fence pattern. The edges of the plate are scalloped with 8 indentations. The ground of the plate has a slightly blue tinge.
It is impressed with the circular mark "PATENT IRONSTONE CHINA" which Geoffrey Godden notes as an early Mason's mark in his book "Mason's China & the Ironstone Wares" (page 224). The plate dates 1813-20.
The plate is in very good condition, with no chips, no cracks, and no repairs. There are glaze skips to the edges of the plate, utensil marks, and wear to the pattern (especially around the outer edge of the interior, likely as a result of stacking). The lustre rim trim is worn away. The plate rings when tapped.
Also, there are two splashes of lustre on the back edge of the plate. They are not chips,(as it might appear in the photo), but were done in the making.