Although the response does not deal explicitly with classical artists, this earlier answer focusing on the life and career of Evelyn Nesbit, one of the most celebrated models of the early 1900s, does offer insight into the way women who posed semi-clothed or unclothed could be treated. You might find it interesting to review it while you wait for fresh answers to your query:

Did being a pin-up girl in the earlier 1900s have the same negative stigma that being a porn star has today?