The overturn and underturn
Okay. Nine lessons in, and we're finally putting the up and down strokes together into something that curves. This is the overturn and the underturn, and once you have these two, you're actually not that far from real letters.
Let me define them plain, because the names don't help much on their own.
The underturn is a down-up: you come down heavy, thick, and at the bottom you curve back up into a thin upstroke. Like a lowercase "n" leg, or half of a "u." Down thick, curve, up thin.
The overturn is the opposite. Up thin, curve at the top, down thick. Like the start of an "m" hump, or half an "h." Up thin, curve, down thick.
And the thing is, these two shapes are in almost every lowercase letter you'll ever write. n, m, u, h, y, r… they're all underturns and overturns stacked together or joined up. So this lesson is worth the slow down.
The mechanics
Same rule as always: pressure on the down parts, ease off on the up parts. You already know that. What's new here is the curve, the part where you're switching from thick to thin (or thin to thick) without lifting the pen and without a hard corner. It should look like a rainbow, not a mountain peak.
Here's how I want you to build it.
Step one — the underturn. Start at the top of your line. Come straight down with pressure, like you've been doing. As you get near the baseline, start easing off the pressure before you hit bottom, not after. That's the part people get wrong — they ride the pressure all the way down and then try to lift at the last second, and you get a hard little corner instead of a curve. Ease off early, curve through the bottom, and come back up thin.
Step two — the overturn. Start at the baseline, thin line, no pressure. Curve up and over, and as you come down the other side, add the pressure back in gradually, not all at once. Same idea in reverse.
Do these separately first. A whole line of just underturns. Then a whole line of just overturns. Don't mix them yet. I know it's tempting to jump to "n" because it looks like a real letter, but you'll bake in a bad habit if the individual shape isn't solid.
Slow. I mean it more here than I've meant it in any lesson so far, because the curve is where your hand wants to rush. It's the part with no straight line to hide behind.
Where people get stuck
The transition point — the exact spot where thick becomes thin — is the whole ballgame. If you release pressure too late, you get a blobby bottom. If you release too early, you get a thin, weak-looking curve that doesn't have any weight to it. There isn't a trick past just doing it slow enough to feel it happening under your hand. You'll feel the nib flex when you're pressing, and you'll feel it stiffen back up when you ease off. Pay attention to that feeling more than the ink for a minute.
I'll say the thing I keep saying: pressure is the whole thing. Shapes are just pressure with a direction attached. If your underturn looks off, it's not that you drew the curve wrong, it's that the pressure changed at the wrong spot on the curve. Fix the pressure timing before you worry about the shape.
A watercolor-brush aside
If you're using one of the water-brush pens — the ones you load with an ink pan or a bit of watercolor — this is a good moment to talk about your water dish, because it matters more here than it did on straight strokes.
I went months not noticing a filmy residue building up on the little dish I use to rinse my brush pen between colors. Just this cloudy spotting, like the dish never came fully clean no matter how I scrubbed it. Turns out it wasn't the dish. It was our water. Hard water, up here, leaves mineral deposits on everything it touches, and that film was just it drying onto the ceramic over and over. Switched to distilled water for rinsing and the problem vanished overnight. Cheap gallon jug from the store, and honestly it made my color lifts cleaner too, not just the dish. If your curves are picking up weird texture or your color's going patchy on the paper, check your water before you blame your hand.
A caution, because it's real
Your hand and wrist are going to want to twist to make these curves happen, especially the overturn. Don't let your wrist do the turning — let your fingers and the pen angle do it, with your arm staying loose. If you're gripping the barrel to force the curve, you'll cramp up in about ten minutes and then you're not learning anything, you're just uncomfortable. Shake your hand out between lines. Seriously, do it, don't skip it because it feels silly.
Before next time
Fill a page with underturns, then a page with overturns, then start mixing them into "u" and "n" shapes if you've got room left. Don't rush to the letters — the curve is the lesson this time.