Here's a subtle marble-like background for use on websites.
Source V. Hartikainen
From a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin
Vertical lines with a bumpy, yet crisp, feel to it.
Source Raasa
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Derived from a corner decoration itself found as a jpg on Pixabay.
Source Firkin
Colour version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Tile-able Dark Brown Wood Background. Feel free to use it as a background image in your designs or somewhere on the web. By the way, the color seems to be close to Coffee Brown.
Source V. Hartikainen
A seamless dark leather-like background texture with diagonal lines that look like stitches.
Source V. Hartikainen
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
A bit strange this one, but nice at the same time.
Source Diogo Silva
It’s an egg, in the form of a pattern. This really is 2012.
Source Paul Phönixweiß
Same as gray sand but lighter. A sandy pattern with small light dots, and some angled strokes.
Source Atle Mo
Just what the name says, paper fibers. Always good to have.
Source Heliodor jalba
Geometric lines are always hot, and this pattern is no exception.
Source Listvetra
Dark Tile-able Grunge Texture. I think this texture can be classified as grunge. It's free and seamless, as always.
Source V. Hartikainen
A gray background pattern with a texture of textile. Suits perfectly for web design.
Source V. Hartikainen
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett