# Set multiple material parameters to null

**URL:** https://forum.dynamobim.com/t/set-multiple-material-parameters-to-null/84061
**Category:** Packages
**Tags:** revit, dynamo, springs
**Created:** [December 12, 2022, 6:39pm UTC](https://forum.dynamobim.com/t/set-multiple-material-parameters-to-null/84061 "2022-12-12T18:39:07Z")
**Posts on this page:** 1
**Showing post:** 4

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### Author: ![bvs1982](https://avatars.discourse-cdn.com/v4/letter/b/43a26b/32.png) [@bvs1982](https://forum.dynamobim.com/u/bvs1982)
#### Post date: [December 12, 2022, 8:01pm UTC](https://forum.dynamobim.com/t/set-multiple-material-parameters-to-null/84061/4 "2022-12-12T20:01:30Z")

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> [@Set Material of Category to Null](https://forum.dynamobim.com/t/set-material-of-category-to-null/64763):
>
> I try to set the material of a Revit Category to Null / Empty. Used the “Set SubCategory Properties” from GeniusLoci, what works well for assigning materials. But how to “deassign”? Inside Revit I can use the Button in the lower left. But how to do this with Dynamo??? THX

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