The number of these hand stamps is very large, but can in the main be assigned to two general types or classes.
The salient features of both types consist of the name of the express in conjunction with the word “Paid”, the distinction between them being that one in addition to these essentals also had the name of the office where the stamp was used, while the other had not.
It will readily be seen that in the first case there may be as many varieties as the company has offices, and that each variety may properly be looked upon as a local provisional of the company, as in fact was the case.
The other type that omits the name of the town partakes more of the character of a regular frank and is much the scarcer of the two. Hand stamps of this class were probably provided by the managing head of the comany in quantities and each office supplied with one to be ready in case of emergency, while the origin of the other was largely the result of energy and pride of local agents.
1. The handstamped franks are nearly exclusively confined to the earliest years od San Francisco’s existence and are consequently mostly to be found on the letter sheets and plain envelopes, before the introduction of embossed envelopes and before the Government rights as to the transmission of most (???) appears to have been properly settled or understood [E. L. Pemberton – St. Cal. Mag] 1872
3. Naturally the oldest franks were merch handstamps, later the companies printed from wood cuts or from type. The different companies connected with each other. Thus a letter delivered to one company frequently bears the handstamps of other companies over whose routes the letter had passed.