A seamless texture of black leather. I think it will look best when used in headers, footers or sidebars.
Source V. Hartikainen
Prismatic Floral Pattern 3 Variation 3 No Background
Source GDJ
Very dark pattern with some noise and 45-degree lines.
Source Stefan Aleksić
This is a remix of "blue wave-seigaiha".I hope this subtle color version of Seigaiha would be suitable for background .
Source Yamachem
This one is super crisp at 2X. Lined paper with some dust and scratches.
Source HQvectors
A seamless pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Hey, you never know when you’ll need a bird pattern, right?
Source Pete Fecteau
One more sharp little tile for you. Subtle circles this time.
Source Blunia
Drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
This is a grid, only it’s noisy. You know. Reminds you of those printed grids you draw on.
Source Vectorpile
Remixed from a design on Pixabay. To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin
This beige background pattern resembles a concrete wall with engravings or something similar to it.
Source V. Hartikainen
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Here's a camo print with more tan and less green, such as might be used in a desert scenario. This is tileable, so it can be used as a wallpaper or background.
Source Eady
Like the name suggests, this background image consists of a pattern of dark bricks. It may be an option for you, if you are looking for something that looks like a brick wall for use as a background on web pages. It's not a masterpiece, but looks pretty nice when is tiled.
Source V. Hartikainen
A dark gray, sandy pattern with small light dots, and some angled strokes.
Source Atle Mo
From a design in 'Storia del Palazzo Vecchio in Firenze', Aurelio Gotti, 1889.
Source Firkin
Tiny little flowers growing on your screen. Nice, huh?
Source Themes Tube
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
Number 1 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
This one needs to be used in small areas; you can see it repeat.
Source Luca
In the spirit of WWDC 2011, here is a dark iOS inspired linen pattern.
Source Atle Mo
Zero CC tileable yellow craft paper; scanned and made by me. CC0
Source Sojan Janso
This is so subtle: We’re talking 1% opacity. Get your squint on!
Source Atle Mo
From a design found in 'History of the Virginia Company of London; with letters to and from the first Colony, never before printed', Edward Neill, 1869.
Source Firkin
This is lovely, just the right amount of subtle noise, lines and textures.
Source Richard Tabor