# VTK grid format/ Boundaries of mesh

**URL:** https://discourse.vtk.org/t/vtk-grid-format-boundaries-of-mesh/7966
**Category:** Support
**Tags:** python, file-formats
**Created:** [March 3, 2022, 12:11pm UTC](https://discourse.vtk.org/t/vtk-grid-format-boundaries-of-mesh/7966 "2022-03-03T12:11:13Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![omarElsayed](https://discourse.vtk.org/user_avatar/discourse.vtk.org/omarelsayed/32/5819_2.png) [@omarElsayed](https://discourse.vtk.org/u/omarElsayed)
#### Post date: [March 3, 2022, 12:11pm UTC](https://discourse.vtk.org/t/vtk-grid-format-boundaries-of-mesh/7966/1 "2022-03-03T12:11:14Z")

</div>

I am trying to create a structured grid using vtk in python. The process is straight forward :

- create points (as numpy array).

- create cells as list of indices from the points list.

How to add boundaries to the mesh? It does not seem to be written in the file format instruction.pdf

" [https://vtk.org/wp-content/uploads/2015/04/file-formats.pdf](https://vtk.org/wp-content/uploads/2015/04/file-formats.pdf) "