I dug out my old flatbed scanner today, plugged it in and put a pair of bananas on it. I left the top open. Halfway through the 10-minutes scanning process, I leaned over it for a moment to get something off a bookshelf. The dark blue of my sweater created the thin line mid-scan. It looked interesting. So I flipped the cover down on the fruit for a minute or so as the scan continued, then flipped it back up after a wide dark bar had recorded.
Then I added a bit of saturation and vignette.