FIRST WATERMARKED STAMPS In 1895, the Bureau of Engraving & Printing re-issued the 1894 stamps with a watermark design (the letters U S P S) to guard against counterfeits. Since a sheet of 100 stamps contained only 81 double-line watermarks, few stamps contain a complete letter in their center. More often, the watermark letter is shifted off-center to either side, or the stamp is straddled by 2 incomplete letters.
