The starting point for this was a texture drawn with the 'Radial Colors' plug-in in Paint.net.
Source Firkin
There are many carbon patterns, but this one is tiny.
Source Designova
You could get a bit dizzy from this one, but it might come in handy.
Source Dertig Media
Bright Multicolored Floral Background by Karen Arnold from PDP.
Source GDJ
This is so subtle I hope you can see it! Tweak at will.
Source Alexandre Naud
I know there is one here already, but this is sexy!
Source Gjermund Gustavsen
An interesting dark spotted pattern at an angle.
Source Hendrik Lammers
This was formed by distorting an image of a background on Pixabay.
Source Firkin
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
I skipped number 3, because it wasn’t all that great. Sorry.
Source Dima Shiper
Prismatic Groovy Concentric Background 5
Source GDJ
Used in small doses, this could be a nice subtle pattern. Used on a large surface, it’s dirty!
Source Paul Reulat
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A seamless green background texture. The image is distributed under a Creative Commons License (like all of the images here).
Source V. Hartikainen
One more sharp little tile for you. Subtle circles this time.
Source Blunia
Prismatic Curved Diamond Pattern 5 No Background
Source GDJ
This is lovely, just the right amount of subtle noise, lines and textures.
Source Richard Tabor
To get the tile this is made up from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
More carbon fiber for your collections. This time in white or semi-dark gray.
Source Badhon Ebrahim
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
In the spirit of WWDC 2011, here is a dark iOS inspired linen pattern.
Source Atle Mo