This is a Scrimshaw Picture that I did a few years ago on Plexiglas.
Scrimshaw is an old Art that the Whalers used to do when they had down time and nothing else to do. They would use Bone, Ivory or Whales Teeth and after sanding it smooth,sometimes with shark skin as sandpaper wasn't readily available then, they would then draw on the Bone or Ivory and begin to carve in lines with a sharpened piece of metal or a knife and then fill in the carved lines with soot,lampblack, or India Ink if they had any. After it was dry they would then rub off the excess,leaving only the coloring in the carved lines.
To do Scrimshaw it takes Hundreds even thousands of carved in lines to make a picture, so this would consume a lot of time, as it does to this day.
This picture that I did is 12x14 on Plexiglas and is framed in wood. It took me over a week to do.
This looks like a pen and ink drawing but it is Scrimshaw and doing it on Plexiglas is much harder to do that on Bone,Teeth, or Ivory because Plexiglas is much harder and therefore takes a lot more pressure to carve in lines. On this one I used a sharpened piece of Carbon steel to do the carving of the lines.