GRENADA 1970 50C PIRATES PROGRESSIVE THERMOGRAPHED COLOUR TRIAL
50c Pirates composite colour trial, on chalk-surfaced, gummed paper measuring circa 53 x 64 mm, combining incomplete typographed background in orange with thermographed figure in red. Ex Bradbury Wilkinson. Very scarce. Generally fresh and fine. SG369var; SC347var
Note: Bradbury Wilkinson experimented with thermography in an attempt to cut escalating engraving costs, but the trial was short-lived as the depth of shading offered wasn't deemed acceptable
