Wavy background #2022
Blue CC 0CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
More Textures
Background pattern 308 (colour 4) #1868
Green CC 0Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
Dark Stitched Leather Background #996
Stripes CC BY-SA 3.0A seamless dark leather-like background texture with diagonal lines that look like stitches.
Source V. Hartikainen
Soft Kill #318
Dark CC BY-SA 3.0Pattern #100! A black classic knit-looking pattern.
Source Factorio.us Collective
Diamond Eyes@2X #686
Diamond CC BY-SA 3.0Everyone loves a diamond, right? Make your site sparkle.
Source AJ Troxell
Spiral pattern 3 #1934
Dark CC 0From a drawing in 'Danmarks Riges Historie af J. Steenstrup, Kr. Erslev, A. Heise, V. Mollerup, J. A. Fridericia, E. Holm, A. D. Jørgensen', 1897.
Source Firkin
One in a Million #1346
Gray CC BY-SA 3.0Nicely executed tiling for an interesting pattern.
Source Ignasi Àvila Padró
White Brushed #1183
Wall CC BY-SA 3.0Brushed aluminum, in a bright gray version. Lovely 2X as well.
Source Andre Schouten
Fruit on a branch #1968
Dark CC 0From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Red Gemstone Tiles #1223
Red CC BY-SA 3.0This tiled background comes in red and consists of tiles that look like gemstones. It is more for blogs or social profiles, I think.
Source V. Hartikainen
Light Wool@2X #696
Grid CC BY-SA 3.0Submitted as a black pattern, I made it light and a few steps more subtle.
Source Andy
Background pattern 232 #2297
Dark CC 0Heavily remixed from a drawing in 'Barbara Leybourne; a story of eighty years ago', Sarah Hamer, 1889.
Source Firkin
"Green Stone", Seamless Web Texture #1050
Stone CC BY-SA 3.0A seamless web texture of "green stone".
Source V. Hartikainen
Grey Washed Wall #1128
Wall CC BY-SA 3.0This is a semi-dark pattern, sort of linen-y.
Source Sagive SEO
Background pattern 215 #2371
Brown CC 0A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
Tex2res1@2X #722
Fabric CC BY-SA 3.0Number 3 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Dark Steel Grid Background Pattern #1081
Metal CC BY-SA 3.0Here's a dark background pattern that contains a steel grid pattern as a texture. Use it as a website background or for other purposes. It's free!
Source V. Hartikainen
Pyramid@2X #896
Light CC BY-SA 3.0Could remind you a bit of those squares in Super Mario Bros, yeh?
Source Jeff Wall
Background pattern 9 (colour) #214
Noise CC 0Colour version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
Vichy@2X #72
Light CC BY-SA 3.0This one could be the shirt of a golf player. Angled lines in different thicknesses.
Source Olivier Pineda
Rebel@2X #830
Dark CC BY-SA 3.0Not the Rebel alliance, but a dark textured pattern.
Source Hendrik Lammers
Decorative divider 246 #2078
Dark CC 0From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin