A bit like smudged paint or some sort of steel, here is scribble light.
Source Tegan Male
Prismatic Basic Pattern 2 No Background
Source GDJ
Just like the black maze, only in light gray. Duh.
Source Peax
A light gray fabric pattern with faded vertical stripes.
Source V. Hartikainen
Remixed from a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
Not sure if this is related to the Nami you get in Google image search, but hey, it’s nice!
Source Dertig Media
This background pattern contains worn out colorful stripes as a texture.
Source V. Hartikainen
Prismatic Geometric Pattern Variation 2 With Background
Source GDJ
And some more testing, this time with Seamless Studio. It’s Robots FFS!
Source Seamless Studio
Seamless pattern the basic tile for which can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A beautiful dark wood pattern, superbly tiled.
Source Omar Alvarado
Prismatic Groovy Concentric Background 4 No Black
Source GDJ
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Geometric triangles seem to be quite hot these days.
Source Pixeden
In the spirit of WWDC 2011, here is a dark iOS inspired linen pattern.
Source Atle Mo
Orange-red pattern for tiled backgrounds.
Source V. Hartikainen
This background has abstract texture with some similarities to wood.
Source V. Hartikainen
Sweet and subtle white plaster with hints of noise and grunge.
Source Phil Maurer
CC0 and seamless wellington boot pattern.
Source SliverKnight
A free green background pattern with a pattern of rhombuses on a seamless texture. Feel free to use it as a tiled background image on your web site.
Source V. Hartikainen
From a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
One more in the line of patterns inspired by Japanese/Asian styles. Smooth.
Source Kim Ruddock