Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
Adapted from an image that was uploaded to Pixabay by Anerma.
Source Firkin
A light gray background pattern with seamless fabric-like texture and almost unnoticeable stripes.
Source V. Hartikainen
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A nice and simple white rotated tile pattern.
Source Another One
Inspired by a pattern seen on a public domain image of a very old tile. To get the unit cell, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Sometimes you just need the simplest thing.
Source Fabricio
And some more testing, this time with Seamless Studio. It’s Robots FFS!
Source Seamless Studio
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 perfect pattern for all your blogs about type, or type-related matters.
Source Atle Mo
Prismatic Groovy Concentric Background 2 No Black
Source GDJ
From a drawing in 'Resa i Afrika, genom Angola, Ovampo och Damaraland', P. Moller, 1899.
Source Firkin
No relation to the band, but damn it’s subtle!
Source Thomas Myrman
A seamless pattern the starting point for which was a 'colour modulo' texture in Paint.net.
Source Firkin
Nasty or not, it’s a nice pattern that tiles. Like they all do.
Source Badhon Ebrahim
Prismatic Geometric Pattern Background 2
Source GDJ
A subtle shadowed checkered pattern. Increase the lightness for even more subtle sexiness.
Source Josh Green
A cute x, if you need that sort of thing.
Source Juan Scrocchi
This white background pattern has a seamless grunge style texture. Here's a white grunge style background pattern. Use it as a tiled background image on web sites or for other purposes.
Source V. Hartikainen