Looks a bit like concrete with subtle specks spread around the pattern.
Source Mladjan Antic
Based on an image that was uploaded to Pixabay by devanath
Source Firkin
It looks very nice I think.
Source V. Hartikainen
Prismatic Groovy Concentric Background 3 No Black
Source GDJ
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Remixed from a drawing in 'Jezebel's Daughter', Wilkie Collins 1880
Source Firkin
A huge one at 800x600px. Made from a photo I took going home after work.
Source Atle Mo
Looks like an old wall. I guess that’s it then?
Source Viahorizon
This reminds me of Game Cube. A nice light 3D cube pattern.
Source Sander Ottens
I scanned a paper coffee cup. You know, in case you need it.
Source Atle Mo
A free seamless background image with a texture of dark red "canvas". It should look very nice on web sites.
Source V. Hartikainen
Dark blue concrete wall with some small dust spots.
Source Atle Mo
The image depicts a seamless pattern of a Japanese family crest called "chidori" in Japanese .A chidori in Japanese means a plover in English.
Source Yamachem
Derived from an image that was uploaded to Pixabay by darkmoon1968
Source Firkin
Prismatic Polka Dots Mark II 3 No Background
Source GDJ
Light gray paper pattern with small traces of fiber and some dust.
Source Atle Mo
A light gray fabric pattern with faded vertical stripes.
Source V. Hartikainen
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
Semi-light fabric pattern made out of random pixels in shades of gray.
Source Atle Mo
Floral patterns will never go out of style, so enjoy this one.
Source Lasma
Alternative colour scheme for the original floral pattern.
Source Firkin