Published 8. March 2020 at 756 × 584 in Exhibition and book presentation Cologne-Kalk: A Fine Art Journey R. Geoffrey Blackburn 7, USA, Castle Tower, 2012, Pigment Print, 10.5 x 14 cm R. Geoffrey Blackburn 7, USA, Castle Tower, 2012, Pigment Print, 10.5 x 14 cm