Freehand

Draw by dragging, like a pen. The stroke is tidied when you let go: the same line, with the points nobody could see removed.

Why you would use it

For the marks that aren’t shapes — a squiggle round something, a tick, a quick sketch of what it should look like instead. Some things are faster drawn than described.

For example

What to do

1. Press and drag.
2. Let go to finish.

Going further

A pointer reports a position every few milliseconds, so one stroke arrives as two or three thousand points. They’re thinned by how far each one sits from the line the stroke would have without it, which keeps the detail in a tight curl and collapses a long straight sweep — typically fifteen times fewer points, and no visible difference. A stroke is moved as a whole rather than reshaped point by point.

If you already use another program

In a CAD program: A sketch line.

In a PDF markup program: A pencil or freehand markup; the stroke is tidied when you let go.