This background has abstract texture with some similarities to wood.
Source V. Hartikainen
Prismatic Groovy Concentric Background 3 No Black
Source GDJ
A bit like some carbon, or knitted netting if you will.
Source Anna Litvinuk
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
I asked Gjermund if he could make a pattern for us – result!
Source Gjermund Gustavsen
A fun-looking elastoplast/band-aid pattern. A hint of orange tone in this one.
Source Josh Green
Remixed from a design on Pixabay. To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Bigger is better, right? So here you have some large carbon fiber.
Source Factorio.us Collective
Background Wall, Art Abstract, white Well & CC0 texture.
Source Ractapopulous
A nice and simple gray stucco material. Great on its own, or as a base for a new pattern.
Source Bartosz Kaszubowski
Seamless Light Background Texture.
Source V. Hartikainen
And some more testing, this time with Seamless Studio. It’s Robots FFS!
Source Seamless Studio
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I. Version with black background.
Source Firkin
You know you can’t get enough of these linen-fabric-y patterns.
Source James Basoo
Nasty or not, it’s a nice pattern that tiles. Like they all do.
Source Badhon Ebrahim
Seamless Dark Grunge Texture. Here's a new grunge texture for use as a background.
Source V. Hartikainen
Remixed from a drawing in 'Очерки Русской Исторіи въ памятникахъ быта', Petr Polevoi, 1879.
Source Firkin
Prismatic Geometric Pattern Background
Source GDJ