Here's a little (blurry) view of a piece that has been sitting on my drawing board, untouched for a month or more until just two days ago, when I finally picked up the pencil again.
I have stared at this section for more hours than I want to recall, while slowly filling in, erasing, filling in, erasing, filling in, erasing, filling in,
you get the idea.
Among the audio books that helped pass the time were "The Thin Man" (Dashiel Hammet) "Every Living Thing" (James Herriot) "The Lord of the Rings" (Tolkien, BBC version.)
So, like I said, hours.
But once you've used a 2B pencil on Stonehenge paper, it's all worth it. MMmmmm, velvety.