Here's a camo print with more tan and less green, such as might be used in a desert scenario. This is tileable, so it can be used as a wallpaper or background.
Source Eady
Some dark 45 degree angles creating a nice pattern. Huge.
Source Dark Sharp Edges
Prismatic Polka Dots Mark II No Background
Source GDJ
With a name this awesome, how can I go wrong?
Source Nikolay Boltachev
An abstract web texture of a polished blue stone (or does it look more like ice).
Source V. Hartikainen
A seamlessly tile-able grunge background image.
Source V. Hartikainen
It’s an egg, in the form of a pattern. This really is 2012.
Source Paul Phönixweiß
Bit of a strange name on this one, but still nice. Tiny gray square things.
Source Carlos Valdez
A free pink background pattern.
Source V. Hartikainen
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
A seamless pattern from a tile made from a jpg on Pixabay. To get the tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A pattern drawn in Paint.net and vectorized in Vector Magic.
Source Firkin
Number five from the same submitter, makes my job easy.
Source Dima Shiper
Fake or not, it’s quite luxurious.
Source Factorio.us Collective
The image depicts a seamless pattern of Japanese Edo pattern called "kikkou-matsu" or "亀甲松" meaning " tortoiseshell-pinetree".The real pinetree is like this: https://jp.pinterest.com/pin/500744052301065077/
Source Yamachem
The image is a design of blue glass.How about using it as background image?
Source Yamachem
Remixed from a drawing in 'Paul's Sister', Frances Peard, 1889.
Source Firkin
Alternative colour scheme. Not a pattern for fabrics, but one produced from a jpg of a stack of fabric items that was posted on Pixabay. The tile that this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Dark wooden pattern, given the subtle treatment. based on texture from Cloaks.
A series of 5 patterns. That’s what the P stands for, if you didn’t guess it.
Source Dima Shiper
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
A dark pattern made out of 3×3 circles and a 1px shadow. This works well as a carbon texture or background.
Source Atle Mo