The D grill measures 12 by 14 millimeters, or fifteen rows or points by seventeen to eighteen rows (the reason that the number of rows sometimes varies within a grill is that they were set only approximately o the grilling machine, so there are slight differences). It is known on two stamps, the two-cent Blackjack (#84) and the three cent (#85). The numbers issued are 200,000 and 500,000 respectively, so that a fair evaluation of the number surviving in collectable condition would be perhaps between 2,000 and 5,000 of each.
The E grill is the second most common grill, measuring eleven by thirteen millimeters (or fourteen by fifteen to seventeen points), and is found on the one cent (#86), two cent (#87), three cent (#88), ten cent (#89), twelve cent (#90), and fifteen cent (#91). Though all E grills are scarcer than the stamps without grill (the 1861 issue), they are not rare. The F grill is the most common of all. It is found on the one cent (#92), two cent (#93), three cent (#94), five cent (#95), ten cent (#96), twelve cent (#97), fifteen cent (#98), twenty-four cent (#99), thirty cent (#100), and ninety cent (#101). This is a very narrow grill, measuring nine millimeters by fourteen millimeters (or eleven to twelve b fifteen to seventeen points), which was the grill the printers finally settled on. Scarcer too than the 1861 issue without grill, none of these stamps rates as rare either.
The rare grill with points down is the Z grill—which is also the most difficult grill to identify. The size of the grill is virtually identical to the E grill. However, the tiny cuts that each pyramid grill cutter makes on the Z grill are horizontal cuts (cuts going across the stamp0 whereas on all other grills these cuts are vertical. While this is a small difference, it is a significant one. The Z grill is generally very rare. There are only three copies known of the one cent with Z grill (#85A). However, due to most collectors’ unfamiliarity with grills, more (though certainly not many more) may be discovered. The two cent with the Z grill (#85B) is the one stamp in the Z grill family that most collectors can aspire to. The number issued is estimated at 100,000; probably a few thousand still exist in collectable condition so it is something of a bargain at its current price of only a few hundred dollars. The three cent Z grill (#85C) is a rare stamp. The ten cent (#85D) is a rarity of the magnitude of the one cent, with only a handful known. The twelve cent (#85E) is not rare, though the fifteen cent (#85F) is another rarity.
The Z grills amply illustrate the problem that philately has with grills. They are difficult to identify and for this reason are overlooked by mot philatelists. Because of their relative unpopularity, rare grills attain nowhere near the high prices that they would achieve if they were “face different” varieties. Man collectors ignore the grills entirely. The two cent Z grill (#85B), which would sell for thousands of dollars if it were a commemorative, only sells for hundreds. Buyers must beware of forged grills, as well. It is not very difficult to attempt to forge a grill on the back of a stamp and to turn a five-dollar variety into an apparent $5,000 one. But such work is rarely convincing to anyone even slightly familiar with grills, though collectors should insist on appropriate authentication or certification on expensive items and would be wise to consult the experts. This is especially true if the time is offered at a “bargain basement” price; it was usually made there.
As an aside, Lester Brookman, one of the greatest experts on United States stamps, believed that there were two main types of collectors: those who suspect that nothing is counterfeit and those who suspect that everything is counterfeit. What he meant is that unknowledgeable collectors (and, increasingly, investors) have no idea how easy it is to create a variety that can look convincing to someone who has never seen it before. At the same time, a little knowledge can make some collectors so skeptical that they never purchase any stamps for their collection. American philatelists are fortunate. Because of firm anticounterfeiting laws, nearly all of the forgeries and alterations of United States stamps are tawdry affairs made quickly before the Feds closed in. knowledgeable experts can tell the grills and any other variety with absolute certainty.