In the spirit of WWDC 2011, here is a dark iOS inspired linen pattern.
Source Atle Mo
A seamless design of flowers remixed from a jpg on Pixabay by Prawny.
Source Firkin
Light gray version of the Binding pattern that looks a bit like fabric.
Source Newbury
Greyscale version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
This is so subtle you need to bring your magnifier!
Source Carlos Valdez
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
That’s what it is, a dark dot. Or sort of carbon looking.
Source Tsvetelin Nikolov
Prismatic Groovy Concentric Background 2 No Black
Source GDJ
A seamless pattern the starting point for which was a 'rainbow twist' texture in Paint.net.
Source Firkin
Neat little photography icon pattern.
Source Hossam Elbialy
From a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
This one is quite simple in design, it consists of vertical stripes layered on top of a seamless texture.
Source V. Hartikainen
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Zero CC tileable hard cover cells book texture, 4k, scanned and made by me. CC0
Source Sojan Janso
A light gray fabric pattern with faded vertical stripes.
Source V. Hartikainen
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
Classic 45-degree pattern, light version.
Source Luke McDonald
Derived from an image that was uploaded to Pixabay by Darkmoon1968
Source Firkin
One of the few full-color patterns here, but this one was just too good to pass up.
Source Alexey Usoltsev
Prismatic Groovy Concentric Background No Black
Source GDJ
A seamless pattern formed from cross 4. To get the original tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
From a drawing in 'Picturesque New Guinea', J Lindt, 1887.
Source Firkin
This is sort of fresh, but still feels a bit old school.
Source Martuchox