A seamlessly repeating background pattern of wood. The image is procedurally generated, and, I think, it's turned out quite well.
Source V. Hartikainen
Used in small doses, this could be a nice subtle pattern. Used on a large surface, it’s dirty!
Source Paul Reulat
Zero CC tileable brick texture, photographed and made by me. CC0
Source Sojan Janso
I skipped number 3, because it wasn’t all that great. Sorry.
Source Dima Shiper
Zero CC tileable hard cover green book, scanned and made by me. CC0
Source Sojan Janso
One more brick pattern. A bit more depth to this one.
Source Benjamin Ward
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
Derived from a drawing in 'The Murmur of the Shells', Samuel Cowen, 1879.
Source Firkin
Colour version that is close to the original drawing uploaded to Pixabay by pencilparker.
Source Firkin
Prismatic Groovy Concentric Background 5
Source GDJ
From a drawing in 'A Life Interest', Mrs Alexander, 1888.
Source Firkin
Background Wall, Art Abstract, Watercolor Vintage style CC0 texture.
Source Ractapopulous
Number 1 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Vertical lines with a bumpy, yet crisp, feel to it.
Source Raasa
Remixed from a drawing in 'Analecta Eboracensia', Thomas Widdrington, 1897.
Source Firkin
I have no idea what J Boo means by this name, but hey – it’s hot.
Source j Boo
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
A free background pattern with abstract green tiles.
Source V. Hartikainen
Feel free to download this "Dark Wood" background texture for your web site. The background tiles seamlessly!
Source V. Hartikainen
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
A seamless pattern formed from a tile made from page ornament 22. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Zero CC tileable hard cover red book, scanned and made by me. CC0
Source Sojan Janso