When I try to draw a line on an image using Preview's annotation tools, it doesn't remain as I drew it but instead the line is drawn linear. How can I set it to be preset as nonlinear?

So looking to the images, I don't want it to be set like this:


Instead I want it to be preset in this way, instead of clicking the actual function everytime to make it nonlinear.

Non Linear

2 Answers 2


In recent versions of Preview there are two annotation tools which seem almost identical: Sketch and Draw.

enter image description here

They both allow you to draw lines, but the difference is that Draw does not try to use shape detection.

Solution: Use Draw instead of Sketch.

Ignore the misleading icons, where it seems that Draw has a thicker line. You can always set the line thickness.

This tool appears only on computers with a Force Touch trackpad, but this is the case for most MacBooks.

Note: As said in a comment under, the Draw tool also changes the thickness of the line depending on Trackpad pressure, so consider this if you want to use the Draw tool as an alternative to the Sketch tool.

It was not a problem in my case, but it may be in yours, depending on how and why you need to draw on the PDF.

  • 1
    The Draw tool changes the thickness of the line depending on Trackpad pressure, so this isn't exactly equivalent to the normal tool.
    – grg
    Feb 19, 2021 at 14:09
  • @grg You are right about this, but while we wait until they (hopefully) will support this, I wanted to provide a workaround for many people who would still be fine with using the Draw tool, at least until this is solved, which was my case and hopefully it could be the OP case. Feb 20, 2021 at 9:58

It's currently not possible to disable the shape detection used by default in the markup tools.

If your drawing is recognized as a standard shape, it’s replaced by that shape; to use your drawing instead, choose it from the palette that’s shown.

Source: https://support.apple.com/kb/PH20218

You can provide feedback to Apple here:

  • Darn. It makes drawing freehand red circles much more difficult. Hopefully they'll let us disable it eventually.
    – Catija
    Jun 16, 2020 at 5:52
  • 1
    @Catija I noticed you commented in 2020. See my answer, it seems that in recent versions this can be solved. Jan 25, 2021 at 5:46

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