I bought a copic sketch pen this summer and haven’t used it much. I’m not sure how well the ink will hold up over time, but I’m really happy with the thin lines I’m getting from it. The fatter lines are from a Tombow brush pen. I haven’t used it very much either, but I will say the ink isn’t very dark. I wouldn’t use it for pages, but it’s fine for sketching. I had to adjust the levels in Photoshop to get the lines black on the scan.