Very dark pattern with some noise and 45-degree lines.
Source Stefan Aleksić
Here's a repeatable texture that resembles a light green concrete wall or something similar.
Source V. Hartikainen
Dark Tile-able Grunge Texture. I think this texture can be classified as grunge. It's free and seamless, as always.
Source V. Hartikainen
Original minus the background
Source Firkin
Derived from an image that was uploaded to Pixabay by darkmoon1968
Source Firkin
emixed from a JPG that was uploaded to Pixabay by Kyotime
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
As simple and subtle as it gets. But sometimes that’s just what you want.
Source Designova
Colour version that is close to the original drawing uploaded to Pixabay by pencilparker.
Source Firkin
You just can’t get enough of the fabric patterns, so here is one more for your collection.
Source Krisp Designs
And some more testing, this time with Seamless Studio. It’s Robots FFS!
Source Seamless Studio
Background Wall, Art Abstract, Block Well & CC0 texture.
Source Ractapopulous
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
This is sort of fresh, but still feels a bit old school.
Source Martuchox
Formed by distorting a JPG from PublicDomainPictures
Source Firkin
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
A very dark spotted twinkle pattern for your twinkle needs.
Source Badhon Ebrahim
I guess this is inspired by the city of Ravenna in Italy and its stone walls.
Source Sentel
Fake or not, it’s quite luxurious.
Source Factorio.us Collective
As the original image 's page size is too large for its image size, I remixed it.
Source Yamachem
A seamless pattern from a tile made from a jpg on Pixabay. To get the tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin