All good things come in threes, so I give you the third in my little concrete wall series.
Source Atle Mo
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
Prismatic Groovy Concentric Background
Source GDJ
Prismatic Abstract Geometric Background 2
Source GDJ
A free black metallic background pattern. Here's a new pattern I made that looks metallic.
Source V. Hartikainen
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
From a drawing in 'Two Women in the Klondike', Mary Hitchcock, 1899.
Source Firkin
From an image on opengameart.org shared by rubberduck.
Source Firkin
A seamlessly repeating background pattern of wood. The image is procedurally generated, and, I think, it's turned out quite well.
Source V. Hartikainen
A good starting point for a cardboard pattern. This would work well in a variety of colors.
Source Atle Mo
This is a semi-dark pattern, sort of linen-y.
Source Sagive SEO
Simple gray checkered lines, in light tones.
Source Radosław Rzepecki
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
If you’re sick of the fancy 3D, grunge and noisy patterns, take a look at this flat 2D brick wall.
Source Listvetra
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
I skipped number 3, because it wasn’t all that great. Sorry.
Source Dima Shiper
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
Alternative colour scheme for the original floral pattern.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A background pattern inspired by designs seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
Can’t believe we don’t have this in the collection already! Slick woven pattern with crisp details.
Source Max Rudberg
I took the liberty of using Dmitry’s pattern and made a version without perforation.
Source Atle Mo
Prismatic Abstract Line Art Pattern Background 2
Source GDJ
A free pink background pattern.
Source V. Hartikainen