The seal is a thick disc of brass. Its upper surface is engraved deeply with the Library Company's emblem, designed by Franklin. Around its rim is the Latin motto, which he composed: Communiter bona profundere deum est. Its free translation is: To pour forth benefits for the common good is divine. On the reverse of the disc is cast a cylindrical stub, perforated with a hole to permit the metal to be fastened to a handle (not present at this time).
Used by the Library Company of Philadelphia, which Franklin co-founded