In my opinion, best to stay away from permanent inks like Noodler’s.
Well, add this lovely pen, and its now quite ruined vinyl sac, to the list of victims of permanent ink.
I received this modern Conway Stewart limited edition pen today with a request for a new ink sac. Getting the section apart revealed the shadowy mess within.
Called the customer and I asked what ink did he use in this pen. The answer was Noodler’s.
In my opinion, I suggest only using inks that are manufactured by pen companies, for they, the pen companies, have a “tacit” responsibility for their inks to work in fountain pens.
By the way, the Noodler’s ink in this pen was only in the pen for about 3 weeks, according to the pen owner. So, in my opinion, best to not put Noodler’s ink in fountain pens.