Grill (philately)

[2] The idea of grilling was first suggested by Charles F. Steel, a supervisor at the National Bank Note Company, with correspondence on the subject dating from 1865.

This would cause the ink cancellation mark to soak into the paper fiber making them more difficult to wash and reuse as postage.

However, the actual practice of grilling on a large scale had not been completely worked out, and the process significantly weakened sheets, resulting in tearing during perforation and general production handling.

National soon switched to the use of a small rectangular pattern of indentations, and subsequent grills were all of this form.

Many of the details have been lost to history; in 1910s, philatelist William L. Stevenson introduced a system of distinguishing types of grills, and identifying them by letter.

Some stamps of the Continental Bank Note Company (who took over production from National) are known to have been impressed with the "J" grill as late as 1875.

Scott moreover lists stamps bearing the experimental J grill as minor variants (denoted by small letters) of non-grilled issues: 156e, 157c, 158e, 159b, 160a, 161c, 162a, 163a, 165c, 179c.

[4] The cover was discovered in 1969 and raised controversy in the philatelic market because certain issues of the much more common "C grill" had been partially erased.