The postal authorities of the United States had a paranoic streak about postal users soaking stamps off envelopes, cleaning off the cancellations, and reusing the stamps. Philatelists who have examined millions of stamps and covers of the period know that this was pure fantasy on the part of the Post Office Department. The hard evidence does not support the theory that cleaning and reusing stamps was a problem of any magnitude whatsoever. Be that as it may, when a customer the size of the Post Office Department tells its printer to look for a way to make such cleaning impossible, the printer usually will find one.
Several schemes were advanced to solve this “problem.” One idea, called patent cancels, was to use a canceller that cut the stamp, as well as canceling it with ink, rendering its reuse unlikely. One small factor, however, was not taken into account: when you cut a stamp on a letter, you cut the letter a well. Postal patrons, who have always complained about the speed of delivery and the condition in which their letters arrived, reacted un enthusiastically when this plan was tried.
Another innovation was to print stamps on a paper that was made by gluing two layers of paper together—a thick bottom layer and a very thin top layer. This was called double paper. In theory, when such a paper was soaked off an envelope, the paper would separate and the top layer on which the stamp was printed would be so thin that the stamp printing would disintegrate. That was the theory! In practice, as often as not, the paper did not separate when soaked because it was glued too well. And sometimes, especially on hot, humid days, the stamp would separate spontaneously. Though philatelists know double paper was tried, especially on the later Bank Note issues, we don’t know how widespread its use was.
Other countries were concerned with philatelic reuse too. The solution effected by Great Britain was to print its stamp on what is called chalky paper, a heavily coated paper that dos not allow the ink to seep deeply into the paper fibers. When soaked off an envelope, the design would often mottle, or spread, and when chemical ink eradicators were used, the stamp would lose their design entirely. Other countries, notably the Dutch Indies, would print some of their stamps in what are called fugitive inks—ink that only lay on the surface of the paper. It is always a treat to see a novice collector’s face when he drops several of these stamps in water to soak and they come out bare and white.
But the United States wanted to keep all of its stamps engraved, and the Great Britain and Dutch Indies answers were not compatible with line engraving. After turning down a brainstorm that would have put a small amount of gunpowder in the stamp paper during the printing process to be detonated by hitting the stamp with the postmark (never, to the Post Office Department’s credit, seriously considered), a man named Charles Steel came up with a plan for a machine that grills.
A grilling machine has tiny pyramids that make minute cuts through the paper after printing and gumming—the theory being that with the paper cut, the canceling ink will seep deeper in, rendering it impossible to clean all evidence of the cancel away. And the little cuts are truly small: most grills cover less than half the stamp and have over 200 tiny cuts. The grills were applied to all of the stamps of the 1861 issue, creating the 1867 issue, and they would not be particularly interesting were it not for the act that being a new process, there was a good deal of trial and error to see what worked. Grill types are referred to by letter (A to L and Z), though only A to F and Z are important to distinguish. A little trick that will aid you in seeing the grill better is to place the stamp face down in a watermark tray and add a bit of watermark fluid. The grill shows up darkly t=in the tray for the simple reason that where the grill breaks the paper, the paper is thinner. Some philatelists use tracing paper and artist’s graphite to measure the grill. They place the stamp face down on a hard surface, place the paper over the stamp, and rub on the graphite. The grill usually shows up well, though this is a cumbersome business. With practice, most grills are easy to see unaided and to identify properly with the use of the tray