I'm a 2d animator and I had this idea to ink cels with brush pens, after using them to ink a different project. The problem is cels have to be inked with a flexible ink, like Higgins T-100 or Koh-I-Noor Rapidraw.
So I want to know if its possible to refill a Pentel cartridge with another ink, specifically one of these two, or is this a horrible idea that will mess up the pen?
Are there other refill brush pen options? Pentel seems to have two other options, "Standard brush" http://www.jetpens.com/index.php/cPath/221_517 and the "Aquash" http://www.jetpens.com/index.php/cPath/221_355 which I don't know if it could handle ink.
Does anyone have experience with any of these pens and experimenting with their ink supplies?
Thanks in advance!