stamp series
at least two postage stamps that are linked by identity of occasion, purpose, event, theme, etc. and similarity of design
en-GB/ˈstæmp ˈsɪəɹiːz/
en-US/ˈstæmp ˈsiɹiz/
at least two postage stamps that are linked by identity of occasion, purpose, event, theme, etc. and similarity of design