McCahon '4 '64 (brushpoint, b.r.); McCahon / May June / 1964 13 (on reverse); C.55. (on reverse, Ikon Fine Arts code)
During this period, McCahon was experimenting with a number of commercial oil and water-based paints. In some cases, he mixed these with artists' oil colours. The exact nature of the medium can be difficult to determine.