Drawn with Linux MyPaint and GIMP.
So far these tools are looking and handling similarly to the Chibi Paint plugin used by Computers Club Drawing Society (among other plugins).
Haven't figured out how to use the hard-edged black and white fill patterns as a brush, yet. I had to make an underlayer in GIMP with that stripe pattern and use the eraser in the top layer to pull it up.
MyPaint has more brushes and effects, a few of which aren't horrible.
Addendum: Am thinking I would like to see this Epson-printed at 17 x 22 inches on some kind of hand-crafted paper resembling a rumpled, brown grocery store bag.
Addendum 2: Added an off-white background.