Dark, square, clean and tidy. What more can you ask for?
Source Jaromír Kavan
This background has abstract texture with some similarities to wood.
Source V. Hartikainen
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.
Source Firkin
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
Background Wall, Art Abstract, Blue Well & CC0 texture.
Source Ractapopulous
Zero CC tileable bark texture, photographed and made by me. CC0
Source Sojan Janso
Remixed from an image that was uploaded to Pixabay by Pixeline
Source Firkin
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Green Web Background, Seamless tile.
Source V. Hartikainen
A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
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
From a drawing in 'Bond Slaves. The story of a struggle.', Isabella Varley, 1893.
Source Firkin
In the spirit of WWDC 2011, here is a dark iOS inspired linen pattern.
Source Atle Mo
Background Wall, Art Abstract, Block Well & CC0 texture.
Source Ractapopulous
Prismatic Groovy Concentric Background
Source GDJ
A seamless texture of a rough concrete surface.
Source V. Hartikainen
One of the few full-color patterns here, but this one was just too good to pass up.
Source Alexey Usoltsev
Remixed from an image that was uploaded to Pixabay by Pixeline
Source Firkin