CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A seamless striped fabric-like texture colored in a dark reddish brown color.
Source V. Hartikainen
A dark one with geometric shapes and dotted lines.
Source Mohawk Studios
A seamless textured paper for backgrounds. Colored in pale orange hues.
Source V. Hartikainen
From a drawing in 'Jardyne's Wife', Charles Wills, 1891.
Source Firkin
More in the paper realm, this time with fibers.
Source Jorge Fuentes
Same as gray sand but lighter. A sandy pattern with small light dots, and some angled strokes.
Source Atle Mo
A pattern formed from a squared tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
It’s an egg, in the form of a pattern. This really is 2012.
Source Paul Phönixweiß
From a drawing in 'Storia del Palazzo Vecchio in Firenze', Aurelio Gotti, 1889.
Source Firkin
A series of 5 patterns. That’s what the P stands for, if you didn’t guess it.
Source Dima Shiper
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Background formed from the original with an emboss effect
Source GDJ
Formed from a tile based on a drawing from 'Viaggi d'un artista nell'America Meridionale', Guido Boggiani, 1895.
Source Firkin
Colour version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
This makes me wanna shoot some pool! Sweet green pool table pattern.
Source Caveman
Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
The tile this fill pattern is based on can be had by using shift+alt+i on the rectangle.
Source Firkin
Sort of like the Photoshop transparent background, but better!
Source Alex Parker
Dark, crisp and subtle. Tiny black lines on top of some noise.
Source Wilmotte Bastien
Very dark pattern with some noise and 45-degree lines.
Source Stefan Aleksić