# Trouble with marking a face in 3D STL files

**URL:** <https://fenicsproject.discourse.group/t/trouble-with-marking-a-face-in-3d-stl-files/1058>\
**Category:** mesh\
**Created:** [June 25, 2019, 5:34am UTC](https://fenicsproject.discourse.group/t/trouble-with-marking-a-face-in-3d-stl-files/1058 "2019-06-25T05:34:55Z")\
**Posts on this page:** 1\
**Showing post:** 2

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**Author:** ![cdaversin](https://yyz2.discourse-cdn.com/free1/user_avatar/fenicsproject.discourse.group/cdaversin/32/44_2.png) [@cdaversin](https://fenicsproject.discourse.group/u/cdaversin)\
**Post date:** [July 8, 2019, 11:40am UTC](https://fenicsproject.discourse.group/t/trouble-with-marking-a-face-in-3d-stl-files/1058/2 "2019-07-08T11:40:33Z")

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Hi,  
Indeed, importing a STL mesh in a geo file (using the `Merge` command) translates each mesh entities into geometric entities (so each triangle of your mesh becomes a surface).

If your original geometry files (STEP) contains face markers, you might be able to import them in your geo file. I haven’t tried it but in case that could help, I have recently read that GMSH has now support for automatic import of labels and colors from STEP files ([https://twitter.com/OnelabModels/status/1102994217247404039](https://twitter.com/OnelabModels/status/1102994217247404039))

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