The little jar of ink came with a small crow quill pen for about 4 bucks. It's been about 80 years since I have used a crow quill pen. Probably before the rollerball was invented. . . so I thought I would give it another try.
Sitting in the parking lot I put the ink to the test. It took a while getting used to the pen, getting reacquainted with the forward motion only. It's not my style any more but I will probably use my investment on a piece soon.
As for the test . . . It worked great. The ink didn't run, even with a very watery brush filled with watercolor.