# Subtraction of surfaces

**URL:** https://discourse.paraview.org/t/subtraction-of-surfaces/5072
**Category:** ParaView Support
**Created:** [August 11, 2020, 1:29am UTC](https://discourse.paraview.org/t/subtraction-of-surfaces/5072 "2020-08-11T01:29:56Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![tejas.canchi](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/t/aeb1de/32.png) [@tejas.canchi](https://discourse.paraview.org/u/tejas.canchi)
#### Post date: [August 11, 2020, 1:29am UTC](https://discourse.paraview.org/t/subtraction-of-surfaces/5072/1 "2020-08-11T01:29:56Z")

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Hi

I have 2 surfaces in stl format and want to subtract the one from the other to create a single stl file. I tried the Booleanoperation.xml filter but I seem to not get the desired result. Is there something I am doing wrong?

I chose the first surface as the outer STL and the second surface as the inner STL and under the properties (Boolean operations), I chose difference.

Thanks