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
Drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
I took the liberty of using Dmitry’s pattern and made a version without perforation.
Source Atle Mo
A background pattern with blue on white vertical stripes.
Source V. Hartikainen
Horizontal and vertical lines on a light gray background.
Source Adam Anlauf
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Simple combination of stripy squares with their negatively coloured counterparts
Source Firkin
Used a cherry by doctormo to make this seamless pattern
Source Firkin
Brushed aluminum, in a bright gray version. Lovely 2X as well.
Source Andre Schouten
Very dark pattern with some noise and 45-degree lines.
Source Stefan Aleksić
An interesting dark spotted pattern at an angle.
Source Hendrik Lammers
Prismatic Geometric Pattern Background
Source GDJ
Prismatic Abstract Geometric Background 5 No Black
Source GDJ
From a drawing in 'Cowdray: the history of a great English House', Julia Roundell, 1884.
Source Firkin
Might not be super subtle, but quite original in its form.
Source Alex Smith
This reminds me of Game Cube. A nice light 3D cube pattern.
Source Sander Ottens
A dark gray, sandy pattern with small light dots, and some angled strokes.
Source Atle Mo
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
The image depicts a Japanese Edo pattern called "kanoko or 鹿の子" meaning "fawn" which has a fur with small white spots.
Source Yamachem
The name alone is awesome, but so is this sweet dark pattern.
Source Federica Pelzel
Classic vertical lines, in all its subtlety.
Source Cody L
A seamless pattern recreated from an image on Pixabay. It is reminiscent of parquet flooring and is formed from a square tile, which can be recovered in Inkscape by selecting the ungrouped rectangle and using shift-alt-I together.
Source Firkin
More carbon fiber for your collections. This time in white or semi-dark gray.
Source Badhon Ebrahim
Super simple but very nice indeed. Gray with vertical stripes.
Source Merrin Macleod
This one takes you back to math class. Classic mathematic board underlay.
Source Josh Green