Little x’es, noise and all the stuff you like. Dark like a Monday, with a hint of blue.
Source Tom McArdle
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Fabric-ish patterns are close to my heart. French Stucco to the rescue.
Source Christopher Buecheler
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
Wild Oliva or Oliva Wilde? Darker than the others, sort of a medium dark pattern.
Source Badhon Ebrahim
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Pattern #100! A black classic knit-looking pattern.
Source Factorio.us Collective
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Here's a brown background pattern with subtle stripes. I hope you'll like the color. If not, feel free to change it using an image editor, if you know how of course. Personally, I'm using GIMP to create these backgrounds.
Source V. Hartikainen
Tiny circle waves, almost like the ocean.
Source Sagive
Could be paper, could be a Polaroid frame – up to you!
Source Chaos
Light and tiny, just the way you like it.
Source Rohit Arun Rao
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Greyscale version of a pattern that came out of playing with the 'slinky' plug-in for Paint.net
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A repeating background for websites with a texture of black groove stripes.
Source V. Hartikainen
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
Another fairly simple design drawn in Paint.net and vectorized in Inkscape.
Source Firkin
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
A free tileable background colored in off-white (antique white) color.
Source V. Hartikainen
Vector version of a JPG that was uploaded to Pixabay by theasad121
Source Firkin
Subtle scratches on a light gray background.
Source Andrey Ovcharov
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
A seamless green background texture. The image is distributed under a Creative Commons License (like all of the images here).
Source V. Hartikainen
Some more diagonal lines and noise, because you know you want it.
Source Atle Mo
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin