Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Drawn in Paint.net and vectorised in Vector Magic
Source Firkin
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
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
A cute x, if you need that sort of thing.
Source Juan Scrocchi
If you like it a bit trippy, this wave pattern might be for you.
Source Ian Soper
A mid-tone gray pattern with some cement looking texture.
Source Hendrik Lammers
A version without colours blended together to give a different look.
Source Firkin
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
This one is super crisp at 2X. Lined paper with some dust and scratches.
Source HQvectors
A car pattern?! Can it be subtle? I say yes!
Source Radosław Rzepecki
One more in the line of patterns inspired by Japanese/Asian styles. Smooth.
Source Kim Ruddock
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
More tactile goodness. This time in the form of some rough cloth.
Source Bartosz Kaszubowski
Remixed from a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
The basic shapes never get old. Simple triangle pattern.
Source Atle Mo
The Grid. A digital frontier. I tried to picture clusters of information as they traveled through the computer.
Source Haris Šumić
A very slick dark rubber grip pattern, sort of like the grip on a camera.
Source Sinisha