Dark and hard, just the way we like it. Embossed triangles makes a nice pattern.
Source Ivan Ginev
A car pattern?! Can it be subtle? I say yes!
Source Radosław Rzepecki
A seamless pale yellow paper background with a pattern of animal tracks.
Source V. Hartikainen
Actually, there's no clouds in it, but I think it looks quite nice.
Source V. Hartikainen
This reminds me of Game Cube. A nice light 3D cube pattern.
Source Sander Ottens
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
Stefan is hard at work, this time with a funky pattern of squares.
Source Stefan Aleksić
Snap! It’s a pattern, and it’s not grayscale! Of course you can always change the color in Photoshop.
Source Atle Mo
Not strictly seamless in that opposite edges are not identical. But they do marry up to make an interesting pattern
Source Firkin
Remixed from a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Used the 6th circle pattern designed by Viscious-Speed to create a print that can be used for card making or scrapbooking. Save as a PDF file for the best printing option.
Source Lovinglf
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
One of the few full-color patterns here, but this one was just too good to pass up.
Source Alexey Usoltsev
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
Classic vertical lines, in all its subtlety.
Source Cody L
Inspired by a drawing in 'Kulturgeschichte', Freidrich Hellwald, 1896.
Source Firkin
Might not be super subtle, but quite original in its form.
Source Alex Smith
Remixed from a drawing in 'Incidents on a Journey through Nubia to Darfoor', F. Ensor, 1891.
Source Firkin
A free background pattern with abstract green tiles.
Source V. Hartikainen
A light gray wall or floor (you decide) of concrete.
Source Atle Mo
Bigger is better, right? So here you have some large carbon fiber.
Source Factorio.us Collective
It almost looks a bit blurry, but then again, so are fishes.
Source Petr Šulc