A huge one at 800x600px. Made from a photo I took going home after work.
Source Atle Mo
A slightly more textured pattern, medium gray. A bit like a potato sack?
Source Bilal Ketab
Beautiful dark noise pattern with some dust and grunge.
Source Vincent Klaiber
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i
Source Firkin
Luxurious looking pattern (for a T-shirt maybe?) with a hint of green.
Source Simon Meek
This one is amazing, truly original. Go use it!
Source Viahorizon
Got some felt in my mailbox today, so I scanned it for you to use.
Source Atle Mo
Prismatic Curved Diamond Pattern 3 No Background
Source GDJ
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Remixed from a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
This one is rather fun and playful. The 2X could be used at 1X too!
Source Welsley
More tactile goodness. This time in the form of some rough cloth.
Source Bartosz Kaszubowski
Abstract Tiled Background Extended 11
Source GDJ
Dark and hard, just the way we like it. Embossed triangles makes a nice pattern.
Source Ivan Ginev
Retro Circles Background 5 No Black
Source GDJ
It’s a hole, in a pattern. On your website. Dig it!
Source Josh Green
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
A seamless pattern the starting point for which was a 'rainbow twist' texture in Paint.net.
Source Firkin