In 1895, the Bureau of Engraving & Printing issued the identical 1894 stamp designs with one significant difference. During the manufacture of the paper, a watermark design was impressed into the paper to guard againsts counterfeits. The design consisted of the letters USPS with "double line" lettering. The "single line" watermark was introduced in 1910.

Unfortunately, due to the size and spacing of the "USPS" letters in the watermark, it is more common to see only portions or fragments of an individual letter. Few U.S. stamps contain a complete letter.

A watermark is best seen by placing the stamp face-down in a black watermark tray and adding a few drops of watermark fluid. The watermark, if there is one, will show up as a slightly darker image than the rest of the stamp. Because the stamp is face down the letters will appear as the mirror image (reversed).