From a drawing in 'Handbook of the excursions proposed to be made by the Lincoln Diocesan Architectural Society, on the 27th and 28th of May, 1857', Edward Trollope, 1857.
Source Firkin
Super subtle indeed, a medium gray pattern with tiny dots in a grid.
Source Designova
Imagine you zoomed in 1000X on some fabric. But then it turned out to be a skeleton!
Source Angelica
A white version of the very popular linen pattern.
Source Ant Ekşiler
Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Actually, there's no clouds in it, but I think it looks quite nice.
Source V. Hartikainen
A new take on the black linen pattern. Softer this time.
Source Atle Mo
This background has abstract texture with some similarities to wood.
Source V. Hartikainen
A beautiful dark wood pattern, superbly tiled.
Source Omar Alvarado
Here's a brown background pattern with subtle stripes. I hope you'll like the color. If not, feel free to change it using an image editor, if you know how of course. Personally, I'm using GIMP to create these backgrounds.
Source V. Hartikainen
The image depicts a seamless pattern of a fishnet with a plenty of fish.It may be a lucky charm for fishermen.
Source Yamachem
Prismatic Abstract Geometric Background 3
Source GDJ
Luxurious looking pattern (for a T-shirt maybe?) with a hint of green.
Source Simon Meek
Heavy depth and shadows here, but might work well on some mobile apps.
Source Damian Rivas
It’s an egg, in the form of a pattern. This really is 2012.
Source Paul Phönixweiß
A bit like some carbon, or knitted netting if you will.
Source Anna Litvinuk
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin