I test my inks in a notebook using a dip pen. But now I'm realizing that I need to also test them in pens before I jump in and buy some. I bought a fine black Preppy at the Chicago Pen Show and decided to fill it with Organics Studio's HMS Beagle. Bad decision. Right away the lines it was making were very wide and the pen was leaking ink practically onto the paper. Of course I have a whole bottle of it. Obviously the Preppy was the wrong pen for it. I turned around 180* and cleaned and filled the Preppy with Noodlers KTC. So far it's behaving itself quite well, but give it time. Now I have to figure out what pen I have can handle the HMS Beagle. Maybe something will come in the mail that will need a free flowing ink like that. I have some Chinese pens winging its way to me.