Fairly rare, yes. Michael has talked about making an effort to work in watercolors about once a year but I've never consciously charted that.
Interestingly, he also had a lot to say about finishing details in gouache to save his fine sable brushes from acrylics. I'm hoping to tease out more process from him about that for an upcoming Q&A.
If I remember correctly, this was one of the rare few covers painted in watercolors?
Fairly rare, yes. Michael has talked about making an effort to work in watercolors about once a year but I've never consciously charted that.
Interestingly, he also had a lot to say about finishing details in gouache to save his fine sable brushes from acrylics. I'm hoping to tease out more process from him about that for an upcoming Q&A.