Submitted as a black pattern, I made it light and a few steps more subtle.
Source Andy
Background Wall, Art Abstract, Block Well & CC0 texture.
Source Ractapopulous
Bit of a strange name on this one, but still nice. Tiny gray square things.
Source Carlos Valdez
If you like it a bit trippy, this wave pattern might be for you.
Source Ian Soper
A seamlessly repeating background pattern of wood. The image is procedurally generated, and, I think, it's turned out quite well.
Source V. Hartikainen
This reminds me of Game Cube. A nice light 3D cube pattern.
Source Sander Ottens
A floral background formed from numerous clones of flower 117.
Source Firkin
This background pattern looks like bamboo to me. Feel free to download it for your website (for your blog perhaps?).
Source V. Hartikainen
Classic vertical lines, in all its subtlety.
Source Cody L
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
Derived from an image that was uploaded to Pixabay by Kaz
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
Light square grid pattern, great for a “DIY projects” sort of website, maybe?
Source Rafael Almeida
Tweed is back in style – you heard it here first. Also, the @2X version here is great!
Source Simon Leo
Old China with a modern twist, take two.
Source Adam Charlts
A simple circle. That’s all it takes. This one is even transparent, for those who like that.
Source Saqib
Horizontal and vertical lines on a light gray background.
Source Adam Anlauf
Remixed from a drawing in 'Hungary. A guide book. By several authors', 1890.
Source Firkin
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Sharp pixel pattern looking like some sort of fabric.
Source Dmitry
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Paper pattern with small dust particles and 45-degree strokes.
Source Atle Mo
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin