Affinity Designer: Inverted mask to below

[AdriZ]

Hi,

I have a curve, I want to transform it in a mask: the layer will be transparent where the curve is present.

The goal is that:

Here it's not a mask, just a black stroke, it's just to understand the result.

 

The problem is, when I click on "Mask to below", the mask is inverted: the curve is revealed, the rest is masked.

 

How can I do?

 

I've attached my .afdesign file.

 

Teeth.afdesign

[carl123]

Mask to below does not work like a regular mask does (which takes into account black and white etc).

It is simply concerned if there is a fill colour or not (the colour does not matter)

Wherever there is a colour that is the part that will show when you use mask to below

[AdriZ]

OK thank you @carl123, I better understand.

But still don't know how to achieve what I would like.

[AdriZ]

I've just found a solution!
And it was really simple...

Found it in the last reply of this post:

Instead of doing a mask, I just have to select "Erase" in Layer option:

[lepr]

1 hour ago, AdriZ said:

But still don't know how to achieve what I would like.

One solution which will allow the design to be exported in vector form is to expand the stroke of the wiggly line to a shape then subtract that from the crescent shape. The screenshot below shows a non-destructive subtraction in a Compound (the app Help explains Compounds).

[AdriZ]

I also add to my solution: I've realized I had to put my stroke inside the below curve, to avoid it to erase other parts of the drawing:

 

Thanks a lot @lepr for your reply.

[lepr]

4 minutes ago, AdriZ said:

Thanks a lot @lepr for your reply.

You're welcome!