I dunked about a hundred scraps of paper with 1c stamps on in cold water today, separating the stamps from the paper.
I was hoping to find just one stamp with an upside-down RSA watermark.
Alas— no such luck with today’s batch of stamps.
This 1c stamp from the Republic of South Africa’s first definitive series (1961) comes with five distinct watermarks:
1. Coat-of-arms
2. No watermark
3. RSA triangles
4. RSA triangles, arranged tête-bêche (one pointing up, one down)
5. RSA triangles, upside down