Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
If you like it a bit trippy, this wave pattern might be for you.
Source Ian Soper
The image depicts a seamless pattern made using a bird's face.
Source Yamachem
From a drawing in 'Prose and Verse ', William Linton, 1836.
Source Firkin
Bright gray tones with a hint of some metal surface.
Source Hendrik Lammers
An orange vertically striped background pattern. Feel free to download and use this orange background pattern, for example, on the web). It resembles a wallpaper with vertical stripes or something similar to it.
Source V. Hartikainen
Prismatic Floral Background No Black
Source GDJ
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
The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
A blue background wallpaper for websites. It has a seamless texture with vertical stripes. It looks quite nice not only when using as a tiled background on websites, but also on computer desktops.
Source V. Hartikainen
Here's a new paper-like background for free use on personal and commercial projects (this applies to all background patterns here).
Source V. Hartikainen
From a drawing in 'Artists and Arabs', Henry Blackburn, 1868
Source Firkin
This reminds me of Game Cube. A nice light 3D cube pattern.
Source Sander Ottens
Little x’es, noise and all the stuff you like. Dark like a Monday, with a hint of blue.
Source Tom McArdle
A brown seamless wood texture in a form of stripe pattern. The result has turned out pretty well, in my opinion.
Source V. Hartikainen
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Got some felt in my mailbox today, so I scanned it for you to use.
Source Atle Mo
The image depicts a seamless pattern of a Japanese family crest called "chidori" in Japanese .A chidori in Japanese means a plover in English.
Source Yamachem
A web texture of brown canvas. Will look great, when used in dark web designs.
Source V. Hartikainen
8 by 8 pixels, and just what the title says.
Source pixilated
Horizontal and vertical lines on a light gray background.
Source Adam Anlauf
Just to prove my point, here is a slightly modified dark version.
Source Atle Mo
This ons is quite old school looking. Retro, even. I like it.
Source Arno Declercq
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
Remixed from a drawing in 'Prehistoric Man: researches into the origin of civilisation in the old and the new world', Daniel Wilson, 1876.
Source Firkin