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
Abstract Geometric Monochrome Pattern Prismatic No Background
Source GDJ
Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
This was formed by distorting an image of a background on Pixabay.
Source Firkin
Never out of fashion and so much hotter than the 45º everyone knows, here is a sweet 60º line pattern.
Source Atle Mo
The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
We have some linen patterns here, but none that are stressed. Until now.
Source Jordan Pittman
A background pattern inspired by designs seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
You could get a bit dizzy from this one, but it might come in handy.
Source Dertig Media
Looks a bit like concrete with subtle specks spread around the pattern.
Source Mladjan Antic
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Farmer could be some sort of fabric pattern, with a hint of green.
Source Fabian Schultz
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Fix and cc0 to get the tile this is based on.
Source SliverKnight
A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.
Source Firkin
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
Real snow that tiles, not easy. This is not perfect, but an attempt.
Source Atle Mo
Seamless pattern formed from a square tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
This is lovely, just the right amount of subtle noise, lines and textures.
Source Richard Tabor