(Response to color values)
You can make believable bamboo many different colors
depending on the light and the scene ... really
... even blue. It's amazing sometimes. There was
a painting I was working on where I could not get
some of the grasses and sticks to look natural. I
"knew" what color they were, but it always looked
artificial on the canvas. Finally, I used an old
trick ... I took a gray card, cut a hole in it
and looked at some of the stuff through that.
It was purple. It was actually purple. And not
only that, some of it was blue. So I painted it
that way and it finally looked real. Of course,
the Impressionists had figured that out a hundred
years before, but they tended to exaggerate it,
so I hadn't believed it up until then.
[Clever response from Stephen Hart: The Impressionists had gray cards?]
Oh, yes. You didn't know? That's where Kodak got the idea.