Grilled Issues of the United States
In the late 1800s, officials were worried that people were “recycling” stamps by washing the cancels away and using them again. So they gambled on an experiment – a grilling machine invented by Charles F. Steel. From 1867-75, Steel’s machine used a roller pitted with either small depressions or small raised pyramids to break fibers in stamp paper. The rollers with depressions created a “points up” pattern while those with raised pyramids made a “points down” pattern.
These broken fibers allowed cancellation ink to thoroughly penetrate the paper. This meant even regular pen ink, which was used to cancel stamps at smaller post offices, would be impossible to remove completely. The experiment was short-lived, ending in 1875.
Early in the 20th century, William Stevenson categorized grills by size and shape, and sorted the stamps by “grill family.” Identifying grills is fun and easy using the pictures and chart below.
“A” Grill – covers the entire stamp; points up/vertical ridges – US #s 79-81
“B” Grill – 18 x 15 mm (22 x 18 points); points up/vertical ridges – US # 82
“C” Grill – 13 x 16 mm (16-17 x 18-21 points); points up/vertical ridges – US # 83
“D” Grill – 12 x 14 mm (15 x 17-18 points); points down/vertical ridges – US #s 84-85
“Z” Grill – 11 x 14 mm (13-14 x 18 points); points down/horizontal ridges – US #s 85A, 85B, 85C, 85D, 85E, 85F
“E” Grill – 11 x 13 mm (14 x 15-17 points); points down/vertical ridges – US #s 86-91
“F” Grill – 9 x 13 mm (11-12 x 15-17 points); points down/vertical ridges – US #s 92-101
“G” Grill – 9.5 x 9 mm (12 x 11-11.5 points); points down/vertical ridges – US #s 112-122
“H” Grill – 10 x 12 mm (11-13 x 14-16 points); points down/vertical ridges – US #s 134-144
“I” Grill – 8.5 x 10 mm (10-11 x 10-13 points); points down/vertical ridges – US #s 134-138
“J” Grill – 7 x 9.5 mm (10 x 12 points); points down/vertical ridges – US #s 156e, 157c, 158e, 159b, 160a, 161c, 162a, 165a, 178c, 179c
Thank you for this very useful information!
I had no idea there is so much detail and engineering that goes into making stamps. There is a whole new dimension to US history that it openned up for me and it’s fascinating.