Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
Not a flat you live inside, like in the UK – but a flat piece of cardboard.
Source Appleshadow
This ons is quite old school looking. Retro, even. I like it.
Source Arno Declercq
From a drawing in 'Worsborough; its historical associations and rural attractions', Joseph Wilkinson, 1879.
Source Firkin
Everyone loves a diamond, right? Make your site sparkle.
Source AJ Troxell
Here's a bluish gray striped background pattern for use on web sites.
Source V. Hartikainen
Same as Silver Scales, but in black. Turn your site into a dragon with this great scale pattern.
Source Alex Parker
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
Number 1 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Prismatic Geometric Tessellation Pattern No Background
Source GDJ
Remixed from a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Here's a quite bright pink background pattern for use on websites. It doesn't look like a real fur, but it definitely resembles one.
Source V. Hartikainen
Fake or not, it’s quite luxurious.
Source Factorio.us Collective
It’s an egg, in the form of a pattern. This really is 2012.
Source Paul Phönixweiß
Not the Rebel alliance, but a dark textured pattern.
Source Hendrik Lammers
This is a remix of "blue wave-seigaiha".I hope this subtle color version of Seigaiha would be suitable for background .
Source Yamachem
Background Wall, Art Abstract, white Well & CC0 texture.
Source Ractapopulous
Prismatic Abstract Geometric Background 4
Source GDJ
A seamless pattern based on a square tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Seamless Light Background Texture.
Source V. Hartikainen
Some more diagonal lines and noise, because you know you want it.
Source Atle Mo
Prismatic Groovy Concentric Background 2
Source GDJ
You could get a bit dizzy from this one, but it might come in handy.
Source Dertig Media