Platinum Carbon Black ink waterproofness and mechanical erasure test

The paper used is Arttec Como Sketch Pad 210gsm paper for mixed media.

Platinum Carbon Black ink is waterproof, but if you re-wet the surface of the paper and then apply friction — with your fingertip, a rubber eraser, or even the bristles of a soft brush — some carbon particles can come off and cause apparent smudging. Those loose particles can most likely be washed off completely, however, without staining the page.

Originally posted here:

https://www.fountainpennetwork.com/forum/topic/355628-struggling-to-find-a-waterproof-black-for-watercolor-sketches/?do=findComment&comment=4357317