The National Bank Company produced separate printing plates for the vignettes and frames of the four stamps that were printed in two colors. The necessity for two plates and two passes through the printing press also led to the first error stamps of the United States. On the bi-color 1869 issue, the vignette was printed on the first pass through the presses, and the frame or Flag and Stars, in the case of the 30¢ stamp, were printed on the second pass.
After the stamp sheets passed through the presses the first time, some were inadvertently returned the wrong-way-round to produce spectacular inverts of the 15¢, 24¢ and 30¢ stamps. There are only three known unused of the 15¢ invert, four of the 24¢, and seven of the 30¢ invert. Known used examples of the inverts range from 36, for the 30¢ stamp, to approximately 90, for the 15¢ stamp.
As mentioned above, the stamps were initially popular with both the public and stamp collectors when they went on sale in March 1869, but unaccountably fell out of favor and had the shortest life span of any U.S. regular postage stamp issued. The stamps were expensive to produce, and the proper alignment of the frames and vignette of the bi-color stamps was difficult to achieve. For those reasons, in October 1869, the Post Office Department gave orders for new stamp designs and instructed Post Offices to return unsold stocks of the issued upon receipt of the new stamps. The new stamps went into use in February of 1870.
