Plate 8 was manufactured about April, 1856 and used continuously until about February 24, 1857, when perforated stamps appeared. All stamps from this plate are Type I, having no inner lines. This plate never showed any wear. Approximately 16,921,800 stamps (84,609 impressions) were printed from Plate 8. Refer to Dr. Chase's book The 3¢ Stamp of the United States 1851-1857 Issue for the full story of Plate 8.
Plate 8 - Earliest Use April 14, 1856; Used for 14 Months; 84,609 impressions/16,921,800 stamps/4367% of issued; 200 Scott 11:
Chase - Plate 8:
Images are provided courtesy of Smithsonian's National Postal Museum