# meshS for a Möbius strip
**URL:** https://community.freefem.org/t/meshs-for-a-mobius-strip/536
**Category:** General Discussion
**Created:** [August 8, 2020, 6:26pm UTC](https://community.freefem.org/t/meshs-for-a-mobius-strip/536 "2020-08-08T18:26:00Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@julienG](https://community.freefem.org/u/julienG)
#### Post date: [August 8, 2020, 6:26pm UTC](https://community.freefem.org/t/meshs-for-a-mobius-strip/536/1 "2020-08-08T18:26:00Z")
Dear all,
Is it possible to build a `meshS` for a Mobius strip? I am trying the following code [mobius.edp](https://community.freefem.org/uploads/short-url/d33T8GolYpjFWnP6B66LKhNOHIi.edp) (508 Bytes), with either `movemesh23` or `square3` functions. Both methods fail with similar error:
> Bad orientation: The adj border element defined by [100 201] is oriented in the same direction in element …
Is it possible to find a workaround, or is it just impossible because the Möbius strip is a non-orientable surface?
Thank you for your help.
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### Author:  [@frederichecht](https://community.freefem.org/u/frederichecht)
#### Post date: [August 9, 2020, 4:26pm UTC](https://community.freefem.org/t/meshs-for-a-mobius-strip/536/2 "2020-08-09T16:26:56Z")
yes, we suppose the surface must be orientable,
sorry.