I have featured the gazania plant in my indoor hydroponic garden a few times over the past 6 months. It has since been transplanted to the yard and is inverted and converted to b&w in this photo.
I like your idea to make an inverted b&w calendar month. I think your technique works very well with flowers, where it emphasizes the complexity and the aesthetism of the patterns. I would have thought that it would mainly work with bright flowers like this one, but it works also very well with darker flowers like your clematitis of yesterday. That makes an original and beautiful calendar page.
