Orange-red pattern for tiled backgrounds.
Source V. Hartikainen
Pattern produced in Paint.net using the Vibrato plug-in.
Source Firkin
A seamless pattern formed from a modified version of rwwgub's tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
If you like it a bit trippy, this wave pattern might be for you.
Source Ian Soper
Prismatic Curved Diamond Pattern 4 No Background
Source GDJ
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
The image depicts meshed silhouettes of various things.The original image is an OCAL clipart called "Enter FOSSASIA 2016 #IoT T-shirt Design Contest" uploaded by "openclipart".Thanks.
Source Yamachem
A free seamless background pattern for use on websites.
Source V. Hartikainen
Cubes as far as your eyes can see. You know, because they tile.
Source Jan Meeus
Not the Rebel alliance, but a dark textured pattern.
Source Hendrik Lammers
From a drawing in 'Royal Ramsgate', James Simson, 1897.
Source Firkin
One more in the line of patterns inspired by Japanese/Asian styles. Smooth.
Source Kim Ruddock
Might not be super subtle, but quite original in its form.
Source Alex Smith
Here's a tile-able wood background image for use in web design.
Source V. Hartikainen
And some more testing, this time with Seamless Studio. It’s Robots FFS!
Source Seamless Studio
Small dots with minor circles spread across to form a nice mosaic.
Source John Burks
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin