This was a fun one! I drew it on a flight to GDC. However, I will note that Sakura Paint Pens ARE NOT air safe. This was almost destroyed by white paint pen ink spilling all over my test page. (Thankfully I was smart enough to actually use a test page before opening the cap.) This did lead to a really funny moment with the guy next to me on the plane giving me a weird look as I stared at my hands covered in white paint! Anyhow, I love making these drawings.