 The new paper was finally employed in stamp production in early 1869 and by 1871 a second series of stamps were issued, printed on a special patented "chameleon" paper containing silk fibers which can be seen in the paper with the naked eye.Still produced by Butler & Carpenter of Philadelphia, the entire second series, with the exception of the 200-dollar issue, were printed in the same bi-color combination, with the portrait of Washington printed in black and with the frame work in blue with various ornate and elaborate designs, popular during that period.The highest values in the second issue of revenue stamps are 200-dollar (left) and the 500-dollar (right) stamps and are commonly referred to by collectors as the Small and Large "Persian rug" revenue stamps respectively, which are considered by many to be among the most colorful and elaborately engraved stamps in all of philately.