The RN-I imprints were the first that Joseph Carpenter of Philadelphia produced. They were the designs of the adhesive bank check and USIR stamps printed by the firm. I1 is the R6 bank check stamp design. It was offered for approximately eight months, but instruments bearing it are not at all common.
The design for I2 was similar, but modeled after the R15 U. S. Internal Revenue two-cent stamp. It was printed for one month in 1867.