The pen tool is four gestures

Everything the tool does

People avoid the pen tool because they think it has a hundred behaviours. It has four, and they are the same in Illustrator, Inkscape, CorelDRAW, Affinity, Figma and Blender.

1. Click. Places a corner anchor with no handles. The segment arriving at it is straight.
2. Click and drag. Places a smooth anchor and pulls out two handles at once, mirror-image, along the direction you dragged. The segment arriving curves into that direction; the segment leaving continues it.
3. Click and drag, then hold Alt and drag again (before releasing, or on the handle afterwards). Breaks the mirror, so the outgoing handle points somewhere the incoming one does not. This is how you get a curve that arrives smoothly and leaves at an angle: a petal tip, the join of a bowl to a stem.
4. Click the first anchor again. Closes the path. Your cursor shows a small circle when you are over it.

That is the tool. Everything else is editing afterwards.

The gesture that trips everyone up

Drag in the direction the curve is going, not towards the shape. Beginners drag towards where they want the line to bend, which points the tangent the wrong way and produces a loop or an S where they wanted an arc.

A useful mental model: the handle is a speedometer and a compass. Direction says which way the pen is travelling as it leaves. Length says how long it keeps going that way before it starts turning.

Getting out of the path

Two problems everybody has in their first hour.

”I can’t stop drawing.” Press Escape (Illustrator, Affinity), Enter or double-click the last point (Inkscape), or Space then Escape (CorelDRAW). Some programs also end a path when you switch tools.

”I started a new shape and it joined onto the old one.” You did not deselect. Press Escape first, every time, before starting a new path. Make it reflex.

Continuing and joining

• Continue an open path: hover the pen over an end anchor until the cursor shows a small slash or a plus, then click.
• Join two open paths: select both end anchors and press Ctrl+J in Illustrator or Ctrl+J in Inkscape (Path ▸ Join nodes). CorelDRAW: select both nodes with the Shape tool and press the Join two nodes button.
• Cut a path: Illustrator’s Scissors (C), Inkscape’s node tool Break path at selected nodes, CorelDRAW’s Break curve.

The drill that works

Take a leaf, a comma and a heart, in that order.

• Leaf: two anchors. One at the tip, one at the base, both cusp. Two curves bulging opposite ways. If you use four, you will see the flat spots.
• Comma: three anchors: top, the outside of the curve, the tail. The tail is the Alt-drag case.
• Heart: four anchors: the two lobes at their outermost points, the dip at the top centre, the point at the bottom. The dip and the point are cusps; the lobes are smooth.

Do each one five times. On the fifth attempt you will place the anchors before you click, which is the whole skill.

Two modifiers worth learning immediately

• Shift while dragging a handle locks it to horizontal, vertical or 45°. At an extreme point (top, bottom, left, right of a curve) the correct handle is exactly horizontal or exactly vertical, so Shift is not a convenience here, it is correctness.
• Space while placing an anchor (Illustrator, Affinity) lets you reposition it before you commit. Saves the undo.

The tool nobody mentions: the pencil

Inkscape’s pencil (P) and Illustrator’s pencil draw a freehand path and fit curves to it, with a smoothing tolerance you can set. For an organic shape drawn on a graphics tablet (a brush mark, a signature, a hand-lettered flourish) it is faster than the pen and produces a better result, because the tangents follow an actual gesture.

It gives you more nodes than a hand-placed path, so simplify afterwards and check the count. For anything geometric it is the wrong tool; for anything gestural it is the right one. Most people never try it and draw wobbly organic shapes with the pen for years.