Inspired by this, I came up with this pattern. Madness!
Source Atle Mo
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
A very dark asfalt pattern based off of a photo taken with my iPhone.
Source Atle Mo
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
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
Sharp pixel pattern looking like some sort of fabric.
Source Dmitry
Bigger is better, right? So here you have some large carbon fiber.
Source Factorio.us Collective
Sweet and subtle white plaster with hints of noise and grunge.
Source Phil Maurer
You may use it as is, or modify it as you like.
Source V. Hartikainen
Love the style on this one, very fresh. Diagonal diamond pattern. Get it?
Source INS
Did anyone say The Hoff? This pattern is in no way related to Baywatch.
Source Josh Green
A pattern drawn in Paint.net and vectorized in Inkscape.
Source Firkin
Light gray paper pattern with small traces of fiber and some dust.
Source Atle Mo
Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Dark pattern with some nice diagonal stitched lines crossing over.
Source Ashton
Remixed from a drawing in 'Analecta Eboracensia', Thomas Widdrington, 1897.
Source Firkin
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
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
This is a seamless pattern of regular hexagon which has a honeycomb structure.
Source Yamachem
From a drawing in 'Navigations de Alouys de Cademoste.-La Navigation du Capitaine Pierre Sintre', Alvise da ca da Mosto, 1895.
Source Firkin