File:Mail-envelope.png licensed with PD-self 2007-10-26T14:35:50Z Producer 543x356 (14146 Bytes) {{Information |Description= A drawing of an envelope |Source=self-made
bytes) {{Information |Description = An [[astroid]] as the [[envelope (mathematics)|envelope]] of a family of lines connecting points (''s'',0), (0,''t'')
English envelope stamped in commemoration of Joao Pandias Calogeras author name string: VenetianNobility Wikimedia username: VenetianNobility determination