Your curves are lumpy because you used too many points

The pen tool is not hard, it is misunderstood

Almost everyone learning vector drawing produces the same result: an outline that looks faceted, with flat stretches between small bumps, and a node count in the hundreds. They conclude the pen tool is difficult. It is not. They are placing points wherever the curve seems to change, and every point they place is another chance to break the curve.

Here is the mechanism. A path is made of anchor points. Between any two anchors the software draws a cubic Bézier curve, and the shape of that curve is set entirely by two handles — one leaving the first anchor, one arriving at the second.

Two properties matter:

• The direction of a handle is the direction the curve travels as it leaves that anchor. The curve is tangent to the handle.
• The length of a handle is how far the curve commits to that direction before it starts turning towards the other anchor.

That is the whole system. Every curve you have ever seen in a font, a logo or a map is this, repeated.

Why more points make it worse

Each anchor imposes a tangent constraint. If you place twenty anchors around a circle, you have declared twenty tangent directions, and unless every single one is exactly right, the curve visibly kinks at each. Four anchors declare four tangents, all of them easy to get right, and the software interpolates a perfect arc between them.

So the rule is not "draw carefully". It is use fewer points, and put them at the extremes.

An extreme is the topmost, bottommost, leftmost or rightmost point of a curve — the place where the tangent is exactly horizontal or exactly vertical. At an extreme, you know the handle direction with certainty, because there is only one correct answer.

Prove it to yourself in two minutes. Draw a circle with the ellipse tool. Switch to the node tool — N in Inkscape, the white arrow A in Illustrator, the Shape tool F10 in CorelDRAW — and look at it. Four nodes: twelve, three, six and nine o'clock. Every handle is perfectly horizontal or perfectly vertical. That is not a coincidence; it is how the shape is defined, and it is how every glyph in every professional typeface is built.

An "S" needs three points. A teardrop needs two curve points and one corner. A leaf needs two. If your leaf has eleven, that is why it looks lumpy.

The habit that fixes it

1. 1Before you click anything, look at the shape and mark the extremes mentally. Those are your anchors. Nowhere else.
2. 2Click and drag at each one. Drag along the direction of travel, holding Shift to lock the handle to horizontal or vertical.
3. 3Make the handle roughly one third of the distance to the next anchor. This is a rule of thumb, not a law, but it gets you close and stops the overshooting bulge that comes from handles that are too long.
4. 4Only then go back and adjust. Adjust handle length before you consider adding a point. Adding a point is almost always the wrong fix.

Where the curve genuinely changes direction — a corner — you want a cusp node, where the two handles move independently. Hold Alt and drag a handle to break the pair in Illustrator and Inkscape; in CorelDRAW, select the node and press the cusp button on the property bar. Where the curve should flow through smoothly, you want a smooth node, where the handles stay in a straight line through the anchor. Inkscape has explicit commands for this on the node tool: Shift+S to make a node smooth, Shift+Y for symmetric, Shift+C for cusp.

The drill

Set a capital S in a heavy typeface at 400 points. Lock it on its own layer at 30% opacity. Trace it with three anchors. You will get it wrong the first four times. When the curve finally sits on the letter with three points, you have learned the thing this lesson exists to teach, and it will not leave you.

Then do a lowercase a, which has an inner counter and a spur, and needs about seven.

Auto-trace is not a shortcut past this

Image Trace, Trace Bitmap and PowerTRACE all place their nodes along the pixel boundary they found, at intervals the algorithm chose. They routinely give you 200 nodes on a shape that needs eight. The result looks acceptable on screen at 100% and reveals its wobble the moment it is enlarged, cut in vinyl or embroidered.

Simplify helps a little — Ctrl+L in Inkscape, Object > Path > Simplify in Illustrator, the node-reduction slider on CorelDRAW's Shape tool property bar — but it removes points by averaging, so it rounds off the corners you wanted to keep while leaving the misplaced points that caused the wobble. Treat a trace as a template to redraw over, not as artwork.

It transfers

This is cubic Bézier geometry, standardised decades ago. The same handles run the pen tool in Figma and Penpot, mask paths in After Effects, curves in Blender, motion paths in animation software, and the outline of every letter you are reading. Learn the handles once and you have learned every pen tool you will ever meet.