The images and annotations below should be of some help in learning to identify #10s. However, plating is the surest method of positive identification, since all stamps printed from plates; 1e, 1i, 2e, 5e, and 0 are defined as #10s, and all stamps printed from plates 1L, 2L, 3, 4, 5L, 6, 7, and 8 are defined as #11s. The #10 shown below is from plate position 33R5e. The #11 is unplated (both stamps were scanned at identical scanner settings).
1) IMPRESSION: The ink used to print #10s was a high-quality formula of approximately 80 percent Venetian red (ferric oxide/rust) and 20 percent vermilion (red mercuric sulfide). The ingredients not only gave the ink its distinctive orange brown color, but it also helped produce a superior impression, and its susceptibility to discoloration is very minimal (rust is the result of being exposed to the elements, and it is not susceptible to significant further discoloration). This first ink formula was discarded after about four months in favor of the brownish carmine shade. The reason for conversion to a new ink formula remains the subject of speculation. The iron oxide/vermilion mix certainly was more expensive, but rapid plate wear caused by the mercuric sulfide may have been an additional factor. Plate wear on this design began to show in the finest lines first. Some #10s printed from plates 1e and 1i do show significant wear. Severe plate wear on this issue is most evident on examples from plate 1L printed in the late-1854 to early-1855 period.
In the image at left, the #10 shown at left is an example of a high-quality early impression, while the #11 shown at right was printed from a severely worn plate, with poor-quality ink. Note the lack of detail in Washington’s head, and the lack of sharpness in the rosettes and especially the tessellated (cross-hatch) work in the #11 impression. The #11 at right was advertised on the Internet as a #10.
2) COLOR: The color and texture of the ink are key factors in #10 identification. Except for some rare anomalies, the color of #10s fall into a narrow range of an orange/brown mix. Although this is stating the obvious, many sellers advertise stamps missing orange, brown, or both colors as #10s simply because their color looks unusual, or deeper, than most 1851-57 3-cent imperforate stamps they’ve seen. The texture of the ink almost always appears thick and rich compared to #11s similar in color. The #11 at right in the above comparison is of the orange red shade, commonly mistaken for orange brown, but the color looks pale and watered down compared to the #10.
“Sulfuretted” stamps are commonly advertised as #10s because of their dark appearance. Sulfuretted stamps are stamps printed with higher concentrations of ferric oxide in the ink formula that have been discolored by exposure to sulfur dioxides (commonly found in air pollutants). Sulfur dioxide (sulfide) exposure converts ferric oxide (found in Venetian Red-based pigments) to ferric sulfate (dark brown).
The image at left shows an orange brown #10 overlaid on a sulfuretted (browned) #11. Close examination of the sulfuretted #11 in the high-resolution image reveals tiny specks of original reddish ink color (arrow) in the low-relief areas in comparison to the blackened higher-relief areas of the inking. The ink used in #10 printings was not susceptible to significant discoloration from exposure to sulfides, although many #11 inks were.
3) CANCELS: Cancellations can be used in limited cases to help confirm or rule out a stamp as a #10. In the 1850s letters generally were carried by the sender to the post office for mailing, and only the stamps needed for that day’s mailing were purchased, and the stamps were immediately affixed to the letters brought for mailing. Stamps used more than a few months after distribution to the post office were the exception. The earliest known use of Scott #10 was July 1, 1851. Approximately 98 percent of #10s were used by the end of May 1852, so examples dated after May 1852 and advertised as #10s should be closely scrutinized (pay close attention to date-lined folded letters). There are only a few confirmed contemporary usages of #10s after 1852 (2/10/53, 6/26/54, and one in 1858), but I’ve seen brazen eBay sellers advertising #10s with 1857 year-dated cancels.
Philadelphia cancels also can be used as dating aids, since Philadelphia abruptly converted from blue to black ink for their cancellation hand stamps on about January 1, 1854. The #11 above, although strong in orange pigment and lacking good plating marks, could not be a #10 because of the black Philadelphia June cancel (and worn-plate impression).
Boston “PAID” cancels also can be used to help confirm a #10. The small-diameter (18mm) “PAID” cancel from Boston (shown in image at left on #10/orange brown) was discarded in favor of the common larger-diameter (24-25mm) “PAID” cancel (shown on #11/brownish carmine) in mid-January 1852. The latest known use of the small Boston “PAID” is January 15, and the earliest known use of the large Boston “PAID” is January 16. While some #10s with the large Boston “PAID” cancel are known, as are some #11s with the small Boston “PAID,” stamps with the small Boston “PAID” will almost always be #10s.
4) PLATING: Although it is not addressed in the comparative images above, plating a stamp using the Smithsonian photographic prints provided by Carroll Chase is the surest way to confirm its identity as a #10. However, a basic knowledge of the characteristics of each plate will allow the educated philatelist to spot misidentified #10s, even in medium-resolution images, without plating them.
5) PROOFS: Plate proofs (Scott #41P3) of the 1875 reprints (Scott #41) of the 1851-57 3-cent issue were made, primarily in the scarlet shade. An example is shown at left. A 41P3 was sold as a #10 on eBay in September 2006.
6) DESIGN TYPE: Design type is not a factor in differentiating #10s from #11s. All 1851 to 1857 3-cent imperforate stamps have an outer frame line on all four sides. Design type 1 (no inner frame lines) can be either Scott #10 or #11. Design type 2 (with inner frame lines) can be either Scott #10A or #11A. I only feel the need to mention this because some of the least educated sellers of stamps on eBay believe all 3-cent stamps from this series with an outer frame line on all four sides are #10 or #10A.
Distinguishing a #10 Plate 1e from a Plate 1i
The differences in plate 1 early versus plate 1 intermediate were caused by the reentry (and not recutting the frame lines (FL’s) or inner lines after the reentry). Early state stamps have clean-cut FL’s and inner lines, where present (refer to Plate 3). Intermediate state stamp FL’s normally have some slight doubling, as well as weak places (refer to Plate 2 late).
Color is another indication. The “Early” state tends to have the pale and yellowish shades. The “Intermediate” state tend to have the “with more red” shades.
It’s difficult to use the Chase photos to determine state, as many stamps have a lot of plate wear (which occurs on both states), and the photographs did not pick up the detail well. And Chase probably has a few assigned to the wrong state.
