John William Waterhouse: Hylas and the Nymphs (1896). This painting is not in the special exhibition at the de Young. I just like it.
Here's your daily dose of confoundingly moronic logic: the M.H. de Young Memorial Museum ( a public, city-owned institution in San Francisco) forbids people from sketching the special exhibitions.
Pencils are allowed in all nooks of New York's Museum of Modern Art, for instance, and the Museum of Fine Arts in Boston only concerns itself with serious replication (as in, "you must obtain a written permit to copy using oils or acrylics, and/or to use an easel"). San Francisco Museum of Modern Art? As long as you don't use a pen, you're fine.
Heck, the Berkeley Art Museum goes so far as to have pencils available at the counter where you buy your ticket.
At the J. Paul Getty Museum in Los Angeles, Clare Kunny of the education department was surprised I even called to ask.
"This is something we highly encourage," Kunny said. "It's an age-old tradition."
I've sketched at the Getty, and anyone who has sketched an original painting (and not just a print, which can never capture the vitality of the original) will attest to the incredible value of this type of study.
De Young draws the line on sketching (Thanks, Jason!)