Just to prove my point, here is a slightly modified dark version.
Source Atle Mo
A seamless pattern created from a square tile. To get the tile, select the pattern in Inkscape and use shift+alt+i.
Source Firkin
The name tells you it has curves. Oh yes, it does!
Source Peter Chon
A free seamless background image with abstract texture of green "curtain".
Source V. Hartikainen
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
A repeating background with dark brown stone-like texture and abstract pattern that looks like tree trunks.
Source V. Hartikainen
Super detailed 16×16 tile that forms a beautiful pattern of straws.
Source Pavel
New paper pattern with a slightly organic feel to it, using some thin threads.
Source Atle Mo
Sweet and subtle white plaster with hints of noise and grunge.
Source Phil Maurer
A seamless pattern with wide vertical stripes colored in pale yellow.
Source V. Hartikainen
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Inspired by the B&O Play, I had to make this pattern.
Source Atle Mo
Pattern formed from simple shapes. Black version.
Source Firkin
The image depicts an edo-era pattern called "same-komon" or "鮫小紋"which looks like a shark skin.The "same" in Japanese means shark in English.
Source Yamachem
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
A blue gray fabric-like texture for websites. An yet another fabric-like texture. It has subtle vertical and diagonal stripes to it.
Source V. Hartikainen
"Beige Stone", Tileable Texture.
Source V. Hartikainen
This light background pattern has a texture of "frozen" surface with diagonal stripes. Here's an yet another addition to the collection of free website backgrounds.
Source V. Hartikainen
Number 3 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
The name is totally random, but hey, it sounds good.
Source Atle Mo
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin