Washington instructed his agents in the use of the "sympathetic stain," noting in connection with "Culper Junior" that the ink "will not only render his communications less exposed to detection, but relieve the fears of such persons as may be entrusted in its conveyance." Washington suggested that reports could be written in the invisible ink "on the blank leaves of a pamphlet. . . a common pocket book, or on the blank leaves at each end of registers, almanacks, or any publication or book of small value."