Here I have tried to create something that would look like maple wood. Not sure how well it's turned out, but at least it looks like wood.
Source V. Hartikainen
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
This is so subtle I hope you can see it! Tweak at will.
Source Alexandre Naud
Prismatic Groovy Concentric Background 4 No Black
Source GDJ
Abstract Tiled Background Extended 8
Source GDJ
Number 2 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
A seamless green background texture. The image is distributed under a Creative Commons License (like all of the images here).
Source V. Hartikainen
Zero CC tileable grass texture, photographed and made by me. CC0
Source Sojan Janso
Heavily remixed from a drawing in 'Barbara Leybourne; a story of eighty years ago', Sarah Hamer, 1889.
Source Firkin
This seamless background image should look nice on websites. It has a dark blue gray texture with vertical stripes, it tiles seamlessly and, like all of the background images here, it's free. So, if you like it, take it!
Source V. Hartikainen
A background pattern with blue on white vertical stripes.
Source V. Hartikainen
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
A background formed from an image of an old tile on the New York Metropolitan Museum of Art website. To get the base tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A nice one indeed, but I have a feeling we have it already? If you spot a copy, let me know on Twitter.
Source Graphiste
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Vertical lines with a bumpy, yet crisp, feel to it.
Source Raasa
A bit like some carbon, or knitted netting if you will.
Source Anna Litvinuk
Dark, lines, noise, tactile. You get the drift.
Source Anatoli Nicolae
Bumps, highlight and shadows – all good things.
Source Badhon Ebrahim
Tiny, tiny 3D cubes. Reminds me of the good old pattern from k10k.
Source Etienne Rallion
This seamless pattern consists of a blue grid on a yellow background.
Source V. Hartikainen
Just like your old suit, all striped and smooth.
Source Alex Berkowitz