Motion 5 Write On "Draw and Erase" not erasing

I’ve run into this problem before, too, and this usually comes down to how the Write On behavior is interpreting your shape stroke, not you doing anything “wrong” in Apple Motion 5.

A few common reasons “Draw and Erase” looks like it’s only drawing:

Your shape has no visible stroke being animated twice

• Write On needs a clear stroke path
• If Fill is dominant and Stroke is thin/hidden, the “erase” phase is basically invisible

Behavior is only set to “Draw” in practice

• In the Write On behavior, make sure the mode is actually set to Draw and Erase Shape Outline, not just Draw with a long duration
• Check if “Erase Duration” is too short to notice (it can look like nothing happens)

Opacity / blend mode masking the erase

• If your second rectangle is using additive / screen / glow style blending, the “erase” may still be there but visually stacking on top

Layer order confusion

• Write On doesn’t erase pixels of another object
• It only affects the stroke of the same shape it’s applied to
• If you’re expecting it to erase the first rectangle, that won’t happen unless you’re using a mask or track matte setup

Better approach for your goal (flare/lens effect)

What you’re trying to achieve (draw over + reveal/erase effect between shapes) usually works better with:

• Mask + Reveal behavior
• or using one shape as a matte for the other
• or using “Subtract” blend mode instead of Write On erase

By the way, “Draw and Erase” only animates the stroke itself — it does not erase another rectangle underneath, which is a super common misunderstanding.

Are you expecting to erase the first rectangle? That is not how it works.

The draw and erase refers to the shape the behavior is applied to.

Here is a very simple example, Rectangle 2 (in red) being drawn and erased over Rectangle 1 (in white).

If you want the second rectangle to appear to erase the first one, you can do it like this:

add the Write On behavior to rectangle 2, as before; add another Write On behavior to rectangle 1, but select "Erase", and time this behavior to match the second part (the erase part) of the behavior in rectangle 2.

So you may get something like this:

Ok - I cannot reproduce the problem you are describing. Does the Erase setting work to erase the rectangle? If you turn off the visibility of the "under" rectangle, does the Write On shape erase? Could you provide a screenshot of what you're seeing that doesn't match what you are expecting?

Did you set up Draw and Erase in the Write On Behavior?