Might not be super subtle, but quite original in its form.
Source Alex Smith
Actually, there's no clouds in it, but I think it looks quite nice.
Source V. Hartikainen
A pattern drawn in Paint.net and vectorized in Inkscape.
Source Firkin
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
A tile-able background for websites with paper-like texture and a grid pattern layered on top of it.
Source V. Hartikainen
Prismatic Curved Diamond Pattern No Background
Source GDJ
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I.
Source Firkin
Colour version that is close to the original drawing uploaded to Pixabay by pencilparker.
Source Firkin
A very slick dark rubber grip pattern, sort of like the grip on a camera.
Source Sinisha
Zero CC bark from fur tree tileable texture, photographed and made by me. CC0
Source Sojan Janso
This one has rusty dark brown texture.
Source V. Hartikainen
This one could be the shirt of a golf player. Angled lines in different thicknesses.
Source Olivier Pineda
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Seamless Olive Green Web Background Image
Source V. Hartikainen
Seamless Background For Websites. It has a texture similar to cork-board.
Source V. Hartikainen
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
Some dark 45 degree angles creating a nice pattern. Huge.
Source Dark Sharp Edges
A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
From a drawing in 'Kingsdene', Maria Fetherstonehaugh, 1878.
Source Firkin
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
You were craving more leather, so I whipped this up by scanning a leather jacket.
Source Atle Mo
A seamless pattern formed from a tile made from ornament 22. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin