Same afternoon a few days ago, seating in the same place, just looking to the right, to the left, or in front of me, I managed to paint several ink-washes in a few minutes each. I am using the pens "Tombow", which are thin on one end, and brush-like at the other end. The ink bleeds quite well, so the minute you touch the design with a brush with water, it bleeds producing very nice effects.
