Twilight Render User Forum

Here is a great source for free textures (free for personal and commercial work!). There's quite a lot of good stuff here.

http://kirkdunne.com/blog/?cat=15

1. https://ambientcg.com/ (NOT packages)
By Struffel Productions
Quantity: 210+
Quality: Up to 8K
Downloads per Day: Unlimited

2. https://www.poliigon.com/ (packages)
Quantity: 52
Quality: Up to 8K
Downloads per Day: Unlimited

3. https://polyhaven.com/textures (packages)
Quantity: 62
Quality: Up to 8K
Downloads per Day: Unlimited

4. https://freepbr.com/ (packages)
Quantity: 107
Quality: Up to 2K
Downloads per Day: Unlimited

5. https://3dtextures.me/ (packages)
By Joao Paulo
Quantity: around 400+
Quality: Up to 1K for Patrons (Premium) up to 4K
Downloads per Day: Unlimited

6. https://www.textures.com/ (packages)
Quantity: 160+ PBR materials, 340+ 3D Scans, and many more
Quality: Up to 1K (Free), Up to 16+K (Premium)
Downloads per Day: 15 Credits/Maps per Day

6 MORE IN ADDITION TO THE 6 ABOVE (from article on https://all3dp.com/2/best-sites-for-free-3d-textures/)
https://www.archivetextures.net/
https://www.sketchuptextureclub.com/textures (packages)
https://www.turbosquid.com/
https://www.arroway-textures.ch (packages)
https://quixel.com/megascans
https://sharetextures.com (packages)