A seamless chequerboard pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i. Alternative colour scheme.
Source Firkin
Lovely pattern with some good-looking non-random noise lines.
Source Zucx
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
Light and tiny, just the way you like it.
Source Rohit Arun Rao
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
Heavily remixed from a drawing that was uploaded to Pixabay by ractapopulous
Source Firkin
From a drawing in 'Jardyne's Wife', Charles Wills, 1891.
Source Firkin
Tiny circle waves, almost like the ocean.
Source Sagive
Sounds like something from World of Warcraft. Has to be good.
Source Tony Kinard
Looks like an old wall. I guess that’s it then?
Source Viahorizon
Traced from a drawing in 'Household Stories from the Collection of the Brothers Grimm', Wilhelm Carl Grimm , 1882.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Colour version of the original pattern inspired by the front cover of 'Old and New Paris', Henry Edwards, 1894.
Source Firkin
A seamlessly tile-able grunge background image.
Source V. Hartikainen
An abstract texture of black metal pipes (seamless).
Source V. Hartikainen
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Could remind you a bit of those squares in Super Mario Bros, yeh?
Source Jeff Wall
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Prismatic Geometric Pattern Background
Source GDJ
This light background pattern has a texture of "frozen" surface with diagonal stripes. Here's an yet another addition to the collection of free website backgrounds.
Source V. Hartikainen
I know there is one here already, but this is sexy!
Source Gjermund Gustavsen
Background Wall, Art Abstract, Block Well & CC0 texture.
Source Ractapopulous
You know, tiny and sharp. I’m sure you’ll find a use for it.
Source Atle Mo
A mid-tone gray pattern with some cement looking texture.
Source Hendrik Lammers
From a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
This one is quite simple in design, it consists of vertical stripes layered on top of a seamless texture.
Source V. Hartikainen
The classic notebook paper with horizontal stripes.
Source Are Sundnes