i’ve used these for quite some time, so i ordered another round, well… going over my outline with these here pens , (brand new) it decided to just start leaking out like the great flood! so build your ARK, and don’t use this for something you have a million hours into cause ya just might waste your time.I ordered these to use with FW acrylic ink, as recommended. They disassemble and fill easily, and the ink flow is rapid and even. The only problem I have found is that the hard nibs are pretty scratchy, even on smooth paper, and tend to flick a lot of very tiny dots of pigment around the page, even when working at a fairly slow speed ... So, probably OK for making dots and lines, but not for filling in larger areas.