That’s it. It’s the ink. Most people leave a small gap between those strokes but with that particular ink it’s not necessary as it doesn’t really behave in the same way as other inks. Whether it’s due to not pooling on the surface or being applied in such a thin layer, I’m not sure. I read in another thread where you stocked up on Higgins Eternal a long time ago. Are you still using the same bottles? Supposedly it was a lot better back in the day. Today’s formula is good and dark, lays down pretty nice, and is very well behaved. There’s even a bit of shading at the tops of letters.