South Africa Airmail Labels - Old designed

These are few old designed South Africa airmail labels found in my old stamps album. Do a quick search on Google, surprisingly South Africa airmail labels are changing very often, there are many variances available. I couldn't recall when I obtained this label as I do not have a proper airmail labels catalog to describe the year in used.

A good advise is to keep the airmail label intact with the postcard or cover. The cancellation postmark will give you the year this label been used. If you collect mint labels from post office, do make sure you record the year. The above shown labels are printed in vertical strip format.