Light gray grunge wall with a nice texture overlay.
Source Adam Anlauf
I scanned a paper coffee cup. You know, in case you need it.
Source Atle Mo
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I.
Source Firkin
A free background pattern with abstract green tiles.
Source V. Hartikainen
Lovely pattern with some good-looking non-random noise lines.
Source Zucx
Produced using the clouds, flames and glass blocks plug-ins in Paint.net and the resulting .PNG vectorised with Vector Magic.
Source Firkin
Luxurious looking pattern (for a T-shirt maybe?) with a hint of green.
Source Simon Meek
Some rectangles, a bit of dust and grunge, plus a hint of concrete.
Source Atle Mo
Just to prove my point, here is a slightly modified dark version.
Source Atle Mo
Colour version of the original seamless pattern.
Source Firkin
Prismatic Abstract Geometric Background 5 No Black
Source GDJ
Three shades of gray makes this pattern look like a small carbon fiber surface. Great readability even for small fonts.
Source Atle Mo
Prismatic Polka Dots 3 No Background
Source GDJ
Background Wall, Art Abstract, Watercolor Vintage style CC0 texture.
Source Ractapopulous
Dark, crisp and subtle. Tiny black lines on top of some noise.
Source Wilmotte Bastien
Otis Ray Redding was an American soul singer-songwriter, record producer, arranger, and talent scout. So you know.
Source Thomas Myrman
A brown metallic grid pattern layered on top of a dark fabric texture. It should look great when using as a tiled background on web pages, especially blogs.
Source V. Hartikainen
Used correctly, this could be nice. Used in a bad way, all hell will break loose.
Source Atle Mo