I have been using Sakura Microns for YEARS. They are 100% waterproof and very saturate. The ink is archival, without a doubt. I have tried other pens - copics, faber-castell, staedtler - and the only ones that come even close to Microns are the Staedtler ink pens. Microns are the best, and I know I will always get great results. Highly recommend, over and over!