Both tools get mods into the game. They do it so differently that the choice shapes everything downstream.
The short answer
Use Penumbra to install and run mods. Use TexTools to make them.
That covers the large majority of people. The rest of this explains why.
How each one works
TexTools modifies the game’s index and .dat files directly. It is a real editor: it can open the game’s file tree, import models and textures, and write them back. That power is also its cost — a bad import corrupts your installation, and every patch day means reverting to a clean state before you can update.
Penumbra does not touch game files at all. It sits in memory and redirects file reads. Nothing to revert, nothing to corrupt, and you can enable or disable a mod instantly without a re-import.
Practical differences
| TexTools | Penumbra | |
|---|---|---|
| Modifies game files | Yes | No |
| Survives patch day | Needs a full revert | Untouched |
| Toggle a mod | Re-import | One checkbox |
| Create new mods | Yes | No |
| Per-character setups | No | Yes, via collections |
The workflow most authors use
- Build the asset in Blender and export it.
- Import into TexTools against a clean game install to check it in the model viewer.
- Export as
.ttmp2. - Test it in-game through Penumbra, where a broken mod costs you one checkbox instead of a re-download.
Keeping a second, clean install purely for TexTools work is worth the disk space if you author regularly.
If you only install mods
You do not need TexTools. Install Penumbra, add Glamourer for appearance control, and stop there. Reach for TexTools the day you want to change something yourself.