A free seamless background texture that looks like a brown stone wall.
Source V. Hartikainen
More tactile goodness. This time in the form of some rough cloth.
Source Bartosz Kaszubowski
Prismatic Hexagonalist Pattern No Background
Source GDJ
This one is super crisp at 2X. Lined paper with some dust and scratches.
Source HQvectors
Black & white 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
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
ZeroCC tileable beechwood wood texture, generated in Neo Texture Edit by me. CC0
Source Sojan Janso
Here's a camo print with more tan and less green, such as might be used in a desert scenario. This is tileable, so it can be used as a wallpaper or background.
Source Eady
Sounds French. Some 3D square diagonals, that’s all you need to know.
Source Graphiste
A huge one at 800x600px. Made from a photo I took going home after work.
Source Atle Mo
Derived from an image that was uploaded to Pixabay by Kaz
Source Firkin
Turn your site into a dragon with this great scale pattern.
Source Alex Parker
From a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
A heavy hitter at 400x400px, but lovely still.
Source Breezi
From a drawing in 'Bond Slaves. The story of a struggle.', Isabella Varley, 1893.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Prismatic Abstract Geometric Background 2 No Black
Source GDJ
The tile this fill pattern is based on can be had by using shift+alt+i on the rectangle.
Source Firkin
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
Prismatic Groovy Concentric Background 5
Source GDJ