About 25 years ago I was doing a lot of blind contour drawings and was looking for just the right pen. I needed constant flow of ink. Smooth fast surface, Quick drying so it would't smear. They last a pretty long time and in bulk are not too expensive. I was using Strathmore 500 series paper and they were the perfect match on that. It has a pretty hard and smooth surface so the speed was available and if you pause briefly it doesn't make a big puddle mark haha.

I got the big box from Blick art supplies really discounted price