# How to use masking in Segment editor

**URL:** <https://discourse.slicer.org/t/how-to-use-masking-in-segment-editor/852>\
**Category:** Support\
**Tags:** segmentation\
**Created:** [August 9, 2017, 8:26pm UTC](https://discourse.slicer.org/t/how-to-use-masking-in-segment-editor/852 "2017-08-09T20:26:49Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![tlooms](https://avatars.discourse-cdn.com/v4/letter/t/c2a13f/32.png) [@tlooms](https://discourse.slicer.org/u/tlooms)\
**Post date:** [August 9, 2017, 8:26pm UTC](https://discourse.slicer.org/t/how-to-use-masking-in-segment-editor/852/1 "2017-08-09T20:26:49Z")

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Hello,

I have been working with the Segment Editor and Segmentation with good  
success. I am very new to 3D Slicer and wondered if there was a tutorial  
that would show how the segments (circles) were drawn in Slide 19. I have  
been using the threshold effect, but cannot figure out how to use the “use  
for masking/paint” feature which I think draws the regions shown in the  
slide(?). Any pointers to documentation or videos would be greatly  
appreciated.

Thanks!

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**Author:** ![lassoan](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/lassoan/32/13_2.png) [@lassoan](https://discourse.slicer.org/u/lassoan)\
**Post date:** [August 10, 2017, 2:30am UTC](https://discourse.slicer.org/t/how-to-use-masking-in-segment-editor/852/3 "2017-08-10T02:30:11Z")

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See [documentation of Segment editor](http://slicer.readthedocs.io/en/latest/user_guide/module_segmenteditor.html). Search for `Masking`.