A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
A dark gray, sandy pattern with small light dots, and some angled strokes.
Source Atle Mo
Neat little photography icon pattern.
Source Hossam Elbialy
Background Wall, Art Abstract, Block Well & CC0 texture.
Source Ractapopulous
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
Dark and hard, just the way we like it. Embossed triangles makes a nice pattern.
Source Ivan Ginev
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
These dots are already worn for you, so you don’t have to.
Source Matt McDaniel
Zero CC tileable moss or lichen covered stone texture, edited from pixabay. CC0
Source Sojan Janso
Number five from the same submitter, makes my job easy.
Source Dima Shiper
Abstract Stars Geometric Pattern Prismatic No Background
Source GDJ
Prismatic Groovy Concentric Background 3
Source GDJ
This one is quite simple in design, it consists of vertical stripes layered on top of a seamless texture.
Source V. Hartikainen
Zero CC Mossy stone tileable texture, photographed and made by me. CC0
Source Sojan Janso
A dark one with geometric shapes and dotted lines.
Source Mohawk Studios
The classic subtle pattern. Sort of wall/brick looking. Or moon-looking?
Source Joel Klein
Inspired by a drawing in 'Kulturgeschichte', Freidrich Hellwald, 1896.
Source Firkin
This is a remix of "geometrical pattern 01".
Source Yamachem
I love the movie Pineapple Express, and I’m also liking this Pineapple right here.
Source Audee Mirza
Black brick wall pattern. Brick your site up!
Source Alex Parker
Feel free to use this seamless background texture as a background on a web site. It's colored in a light pink color and is seamlessly tile-able.
Source V. Hartikainen
In the spirit of WWDC 2011, here is a dark iOS inspired linen pattern.
Source Atle Mo
Awesome name, great pattern. Who does not love space?
Source Nick Batchelor
Prismatic Isometric Cube Wireframe Pattern No Background
Source GDJ
Everyone loves a diamond, right? Make your site sparkle.
Source AJ Troxell