Hello Crit Group Friends - Hope it is OK to post this update to our conversation last night.
I was fascinated with Susan's paintings using the pigment Purple Lake. It seemed so unusual, yet so effective in landscape paintings. Susan's tube was Purple Lake from Windsor Newton, as shown on the right above. I wondered if Gamblin made a similar pigment. The closest I could find was Gamblin's Quinacridone Violet, shown at the left above. I am guessing that the Gamblin color would be more intense in its tinting strength, and it definitely seems cooler.
I bought a tube of the Purple Lake this morning and look forward to the next time I am painting on a bright, hot day!