Airgraph Types Specialist collectors of Airgrahs recognise four major types of UK Airgraph envelopes, with 15 varieties. Airgraph collecting can easily become quite complex Type 1 envelopes have winged arrow symbol with rectangular window Type 2 envelopes have winged arrow symbol with oval window, 'No. 243.' above symbol. Type 3 envelopes have cloud symbol with oval window (Envelopes from the Christmas period have red square in place of day in date, or no date at all) Type 4 envelopes - As type3 but cancel in blue, made and printed by Dickinson. All except type4 are found with wavy line (Universal) or double ring (Pitney Bowes) cancels