An interesting dark spotted pattern at an angle.
Source Hendrik Lammers
Zero CC tileable bark texture, photographed and made by me. CC0
Source Sojan Janso
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
This is the third pattern called Dark Denim, but hey, we all love them!
Source Brandon Jacoby
Tiny little flowers growing on your screen. Nice, huh?
Source Themes Tube
Sharp but soft triangles in light shades of gray.
Source Pixeden
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Orange-red pattern for tiled backgrounds.
Source V. Hartikainen
f you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
Prismatic Abstract Geometric Background 4
Source GDJ
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
Greyscale version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
Luxury pattern, looking like it came right out of Paris.
Source Daniel Beaton
Lovely pattern with some good-looking non-random noise lines.
Source Zucx
Might not be super subtle, but quite original in its form.
Source Alex Smith
Same as Silver Scales, but in black. Turn your site into a dragon with this great scale pattern.
Source Alex Parker
Prismatic Curved Diamond Pattern 6 No Background
Source GDJ
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
This is a hot one. Small, sharp and unique.
Source GraphicsWall
A seamless pattern of dark bricks. Maybe it's not very realistic, but it looks good in my opinion.
Source V. Hartikainen
Remixed from a JPG that was uploaded to Pixabay by theasad121
Source Firkin
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin