# Creating a smooth circle (without dents)

**URL:** <https://discourse.psychopy.org/t/creating-a-smooth-circle-without-dents/28281>\
**Category:** Builder\
**Tags:** screen\
**Created:** [March 29, 2022, 12:28pm UTC](https://discourse.psychopy.org/t/creating-a-smooth-circle-without-dents/28281 "2022-03-29T12:28:05Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![laurencehunt](https://avatars.discourse-cdn.com/v4/letter/l/e68b1a/32.png) [@laurencehunt](https://discourse.psychopy.org/u/laurencehunt)\
**Post date:** [March 29, 2022, 12:28pm UTC](https://discourse.psychopy.org/t/creating-a-smooth-circle-without-dents/28281/1 "2022-03-29T12:28:05Z")

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**OS** (e.g. Win10): Apple Mac, Monterey (12.1)  
**PsychoPy version** (e.g. 1.84.x): 2022.1.1  
**Standard Standalone? (y/n)**: y

I am trying to draw a circle that is transparent in the middle in Builder using the polygon component (I have set Fill Color to “None”). The circle needs to have a thick perimeter (so I have set Line Width to 20). When I draw the circle, it draws appropriately, but has four ‘dents’ in the corners (see attached screenshots). Is this a known problem?

If I draw a filled circle (with a thin line width), then the circle appears as normal, but my experiment needs the circle to be transparent in the middle. Any suggested workarounds most welcome.

 ![Screenshot 2022-03-29 at 13.00.02](https://us1.discourse-cdn.com/flex002/uploads/psychopy/original/3X/e/0/e0d73e6d7e7a5645bfeeda87f8f2b15e9bdb3722.png)  
 ![Screenshot 2022-03-29 at 13.25.21](https://us1.discourse-cdn.com/flex002/uploads/psychopy/original/3X/d/a/da274179e117268ecc493cce52c2bc4195246bde.jpeg)

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**Author:** ![wakecarter](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.psychopy.org/wakecarter/32/5753_2.png) [@wakecarter](https://discourse.psychopy.org/u/wakecarter)\
**Post date:** [March 29, 2022, 12:56pm UTC](https://discourse.psychopy.org/t/creating-a-smooth-circle-without-dents/28281/2 "2022-03-29T12:56:57Z")

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This looks similar to one I came across a while ago. The solution there was to use two overlapping filled circles (the smaller one being the colour of the background).

> [@Circles losing pixels, magnified upon enlarging](https://discourse.psychopy.org/t/circles-losing-pixels-magnified-upon-enlarging/14226/4):
>
> New suggestion. It could be an issue with the borders. How about trying two solid circles with no border: a smaller grey one on top of a larger white one.

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**Author:** ![laurencehunt](https://avatars.discourse-cdn.com/v4/letter/l/e68b1a/32.png) [@laurencehunt](https://discourse.psychopy.org/u/laurencehunt)\
**Post date:** [March 29, 2022, 1:36pm UTC](https://discourse.psychopy.org/t/creating-a-smooth-circle-without-dents/28281/3 "2022-03-29T13:36:44Z")

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Thanks for the suggestion! Unfortunately it’s not quite what I’m looking for (I was planning to use the outer circle as a mask for another stimulus that is non-circular, to give it circular edges) - but I suppose I might be able to make something like this work with multiple overlapping rings.

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**Author:** ![laurencehunt](https://avatars.discourse-cdn.com/v4/letter/l/e68b1a/32.png) [@laurencehunt](https://discourse.psychopy.org/u/laurencehunt)\
**Post date:** [March 29, 2022, 1:43pm UTC](https://discourse.psychopy.org/t/creating-a-smooth-circle-without-dents/28281/4 "2022-03-29T13:43:38Z")

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Silly me! I should have just used the aperture component all along. Problem solved 🙂