One single line and no skipping. I love this pen. TWSBI Mini F, inked with Iroshizuku Ku Jaku.
Update: Two years later: No more TWSBI. The nib unit cracked and a small piece broke off. A pen in this price range should last longer than 2 years. Lamy is cheaper and way more durable. My $3.75 Preppy last longer than 2 years. TWIBI was non-responsive.