Looks a bit like concrete with subtle specks spread around the pattern.
Source Mladjan Antic
ZeroCC tileable stone texture, edited from pixabay. CC0
Source Sojan Janso
Don’t look at this one too long if you’re high on something.
Source Luuk van Baars
Cubes as far as your eyes can see. You know, because they tile.
Source Jan Meeus
Remixed from a drawing in 'A Child of the Age', Francis Adams, 1894.
Source Firkin
Remixed from a JPG that was uploaded to Pixabay by susanlu4esm
Source Firkin
A blue gray fabric-like texture for websites. An yet another fabric-like texture. It has subtle vertical and diagonal stripes to it.
Source V. Hartikainen
Clover with background for St. Patrick's Day. Add to a card with a doily, ribbon, a leprechaun or other embellishments.
Source BAJ
Seamless Olive Green Web Background Image
Source V. Hartikainen
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Looks like an old wall. I guess that’s it then?
Source Viahorizon
Background Wall, Art Abstract, Star Well & CC0 texture.
Source Ractapopulous
Brushed aluminum, in a bright gray version. Lovely 2X as well.
Source Andre Schouten
An orange vertically striped background pattern. Feel free to download and use this orange background pattern, for example, on the web). It resembles a wallpaper with vertical stripes or something similar to it.
Source V. Hartikainen
Carbon fiber is never out of fashion, so here is one more style for you.
Source Alfred Lee
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Derived from an image that was uploaded to Pixabay by starchim01
Source Firkin
Scanned some rice paper and tiled it up for you. Enjoy.
Source Atle Mo
Seamless pattern the basic tile for which can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A seamless web texture of "green stone".
Source V. Hartikainen
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
A simple example on using clones. You can generate a nice base for a pattern fill quickly with it.
Source Lazur URH
Alternative colour scheme for the original floral pattern.
Source Firkin
This one takes you back to math class. Classic mathematic board underlay.
Source Josh Green