South Africa 1925 Airmail

 Despite its vast size, South Africa was extremely slow to introduce an air mail service to speed up the delivery of local mail. 

Eventually, in 1925, the Civil Air Board in South Africa decided to institute a three monthly Experimental Air Service between Cape Town and Durban

A set of four Air Mail stamps was specially printed specifically for the Experimental Air Service that was inaugurated on 2 March 1925. 

The stamps were only valid for the Airmail surcharge, thus ordinary stamps had to be employed for the normal postage rate.

Remainders and plates were destroyed after valid period use

Postmaster General Souvenir Sheet

Genuine  & Forgeries
The forgeries are numerous and from a typical online image, very difficult to ID

The forgeries are perforated 11½ instead of 12.

Apparently, the design is about ¼ mm. narrower in width and ¾ mm. shorter in height than on the genuine stamp. I have not verified this.

The background lines tend to be uneven especially on the ends

A much easier method to ID them are the specific flaws found on each value.

1d - Very short upper serif on the left ‘1’

3d - Small spot of color on the horizontal line below the right leg of ‘A’ in AIR

6d - ‘U’ in SUID is broken. Spot of color above ‘I’ in SUID

9d - Small spots of color connects the lines in the background below ‘O’ in SOUTH

Full set of forgeries posted on eBay as genuine