After the introduction of stamps in the mid 1800s, postmarking was a two-step process. First, postage stamps were 'cancelled' by using either an ink pen or a handstamp. The second step was to 'postmark' the mail piece to indicate the mailing location and date. Additional markings, known as 'auxiliary marks', might be added to give more specific processing directions, such as 'PAID', 'FREE', or 'Return to Sender'.
Although commercially-made handstamps were available, either supplied by the Post Office Department or ordered by a postmaster from a supply house, many of these were hand-crafted by an artistic or handy postal employee. Often, the printing surface was carved from wood, although other materials such as cork, rubber, or metal were used. Generally, the softer the media that was worked, the more limited life of the marking device, and the less likely the handstamp has survived. Meanwhile, the imprints they left behind are often sought-after by postal history collectors.