These stamps were issued on 22 June 1930 for the Großflugtag (Regensburg Great Flight Day).
These stamps were issued on 12 April 1925 for the Regensburger Osterflugtage (Regensburg Easter Flight Days).
This stamp was issued for use on the first Hessian glider mail, 19 October 1930.
Shown below are the stamps of the GermanStamps.net Collection on the physical album pages.
Unlike official airmail stamps, semi-official airmail stamps were issued by aviation companies, air shows, and other aviation-related organizations. The semi-official airmail stamps paid the fee for transport of the mail on a particular airplane, glider, or balloon flight.