HANDSTAMPED

Noun
1. a stamp (usually made of rubber) for imprinting a mark or design by hand
(synonym) rubber stamp
(hypernym) seal, stamp
(derivation) rubberstamp
Verb
1. stamp with a rubber-stamp, usually an indication of official approval on a document
(synonym) rubberstamp
(hypernym) stamp
(derivation) rubber stamp

Postmarked or canceled by hand, usually by a rubber stamp, may also be a steel device.