Cachet: A stamp-related design on an envelope.
Cancellation: A mark placed on a stamp by a postal authority to show that the stamp has been used.
First Day Cover: Envelopes bearing unused stamps postmarked on the first day of issuance, either in black ink or with a colorful digital design inspired by the artwork.
Packet: A presorted group of different stamps, a common
and economical way to begin a stamp collection.
Perforations: Lines of small holes or cuts between rows of stamps that make them easy to separate.
Postmark: A mark put on envelopes or other mailing pieces showing the date and location of mailing.
Selvage: The paper around panes of stamps, sometimes called the margin.