This sketch was a real challenge. It might not look like it. It is a simple shape, simple lines. What I had real difficulty with was the fact that this shell had a lot of calcium deposits on it, making it an odd patchwork of white and pale grey. I finished it, and later had to go back in, because it was such a pale drawing, and I had no contrast or interest going at all. I added darker shadows beneath it, and it just popped right out! Sometimes I miss the obvious, and the basic training I have had flies out of my brain. I need more focus! The holidays must have sapped my common sense and left me flighty and muddle-headed!