Duplex cancel

A duplex cancel consists of two parts, a CDS or similar postmark plus a killer/obliterator. There are many, many different styles. The ideal is that the killer positively cancels the stamp while the CDS is struck alongside on the envelope in one go. While this often happened as intended, there were always cases where multiple stamps required multiple cancel strikes regardless.

This generally handstamped cancel can be struck by a device with both parts permanently together. There are versions where the killer is removable to allow cancellation of multiple stamps.  File:New York 46 duplex.jpg|New York City duplex with "46" in the killer portion. File:Duplex cancel.png|striking end of an RMS cancel hammer. Note spaces and slugs that allowed changing data including the trip number. File:US New Orleans postal card.jpg|US New Orleans duplex on 1893 postal card to Germany. 

[[Category:D]]