A seamless dark leather-like background texture with diagonal lines that look like stitches.
Source V. Hartikainen
A hint of orange color, and some crossed and embossed lines.
Source Adam Anlauf
This is a remix of "blue wave-seigaiha".I hope this subtle color version of Seigaiha would be suitable for background .
Source Yamachem
This seamless pattern consists of a blue grid on a yellow background.
Source V. Hartikainen
Very simple, very blu(e). Subtle and nice.
Source Seb Jachec
Prismatic Rounded Squares Grid 4 No Background
Source GDJ
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Prismatic Curved Diamond Pattern No Background
Source GDJ
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
An attempt for cleaning up the original image in a few steps.
Source Lazur URH
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i
Source Firkin
Sometimes you just need the simplest thing.
Source Fabricio
It almost looks a bit blurry, but then again, so are fishes.
Source Petr Šulc
A comeback for you: the popular Escheresque, now in black.
Source Patten
Prismatic Triangular Background Design Mark II 5
Source GDJ
First pattern tailor-made for Retina, with many more to come. All the old ones are upscaled, in case you want to re-download.
Source Atle Mo
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Hexagonal dark 3D pattern. What more can you ask for?
Source Norbert Levajsics
A repeatable image with dark background and metal grid pattern.
Source V. Hartikainen
Sort of reminds me of those old house wallpapers.
Source Tish
Small gradient crosses inside 45-degree boxes, or bigger crosses if you will.
Source Wassim
Abstract Stars Geometric Pattern Prismatic No Background
Source GDJ
Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin