No convincing argument has been made for the 12¢ stamp's specific planned role according to the postal rates and documents of the period, and no known Post Office references are available at this time to indicate specific intended uses. The U.S Postal Guide and Advertiser of the 1851 listed a few rate cases where the 12¢ stamp or multiples of it might be construed to apply. The rates were for various domestic prepaid uses: for any distance not over 3000 miles, 1.5-2.0 oz (12¢ or the "quadruple rate"); for any distance over 3000 miles, .5-1.0 oz. (12¢ or the double transcontinental rate); 1.5-2.0 oz (24¢ or the quadruple transcontinental rate); for any distance over 3000 miles to British North America Provinces, 1.5-2.0 oz. (60¢); and six more transient newspaper rates! None of these turned out to be the major uses for the stamp except possible for the "quadruple" rate. The only transatlantic postage rate listed in the 1851 Postal Guide that is a listed multiple of 12¢ is that to Great Britain (24¢). This specific use of the 12¢ stamp is not called out in the Guide.

Domestically, it was used to make up a variety of multiple rates, perhaps heavier letters in combination with 3¢ stamps and the transcontinental use. All of the aforementioned rates except the postal use to Great Britain turn out to be fairly scarce, if not exceptionally rare, usages.

While Plate One stamps have been "plated" (each stamp position defined by its own peculiar plate characteristics), improvements in this knowledge continue.

All 200 positions (2 panes of 10 rows by 10 columns of stamps on an engraving plate of 200 total impressions, divided by a centerline) were recut and strengthened to some degree because of less than desirable printing results. Most of the work was done on the inner and outer frame lines. However, the engraving rework was done with such extraordinary skill that only after some practice could students learn to detect much of the work. Overall, the work was phenomenal. Characteristic "position dots" on most of the stamps are key in identifying the majority of the 200 positions.

The stamps from Plate One were issued perforated as well. Imperforate sheets of stamps were fed into perforating devices to create these new stamps. The earliest verified use is July 30, 1857. By this date, the use of the 12¢ stamps had increased quite a bit, particularly with mail to France and Great Britain, as well as domestically, with multiple weight letters, many of a legal nature.

Government records indicate that a second plate was produced for the 12¢ stamp (and returned to the engraver at a later date). It is believed that the plate was later destroyed in a fire in Philadelphia. No one knows why, but it is presumed that this new plate would have a new design to provide more inter-stamp spacing between the perforations that were being introduced. No evidence has been discovered to confirm any stamps produced from this "mystery plate". Nothing is known about this plate or the appearance of the stamps if any were ever produced even on a trial basis.

The earliest verified use of perforated stamps from this plate is June 1, 1860. A new, bolder engraver inscription was used in the margin of the plate and a number "3" identified this new plate. The printing plate was again composed of right and left panes of 100 stamps each separated by a centerline that would be cut through to separate the panes of stamps. Stamp spacing was increased horizontally to make room for the perforations. While one would expect that in the intervening period since Plate One, that much improvement was made in stamp production and quality, but that was not to be the case with Plate Three. The stamps are of relatively poor quality, missing part or all of many of the frame lines, are blurred in appearance, and were on poorer quality paper. Larger volume of stamp production, costs, time, contract pressures and variety of other issues no doubt all contributed to this situation.

While this stamp is now over 150 years old, new discoveries continue to be made.

It was always believed that a single-relief transfer roll (the metal roller used to impress each of the 200 stamp entries on the master printing plate) was used to prepare the 12¢ plate. In 2000, it was discovered that two-relief roll was used to produce the plate. This was determined after careful study of many vertically adjoining "plated" stamps.

Plate One was known to have a plate inscription (called an "imprint") on both the left and right sides of the plate identifying the engraver "Toppan, Carpenter, Casilear & Co., Bank Note Engravers, Phil., New York, Boston, & Cincinnati". It was believed this inscription was on the Plate One from it inception. In 2001, a block of four stamps was discovered with large margins that, because of the stamps plated position, should have contained the inscription imprint. It did not, and, therefore it was then concluded that the Plate One existed in an "early state" without the imprint and a "late state" with the imprint. No one knows if other more subtle engraving changes were made at the same time as these changes were made.

Who knows what other discoveries await other curious collectors and researchers of this stamp, which was issued over 150 years ago? Future collectors who assume that there are many things yet to learn about this stamp will provide the answers!