A seamless pattern the starting point for which was a 'colour modulo' texture in Paint.net.
Source Firkin
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
Derived from an image that was uploaded to Pixabay by Kaz
Source Firkin
The name Paisley reminds me of an old British servant. That’s just me.
Source Swetha
A light gray wall or floor (you decide) of concrete.
Source Atle Mo
Hexagonal dark 3D pattern. What more can you ask for?
Source Norbert Levajsics
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
The tile this fill pattern is based on can be had by using shift+alt+i on the rectangle.
Source Firkin
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
Lovely pattern with some good-looking non-random noise lines.
Source Zucx
In the spirit of WWDC 2011, here is a dark iOS inspired linen pattern.
Source Atle Mo
Thin lines, noise and texture creates this crisp dark denim pattern.
Source Marco Slooten
Hey, you never know when you’ll need a bird pattern, right?
Source Pete Fecteau
Prismatic Groovy Concentric Background No Black
Source GDJ
A seamless pattern formed from a rectangular tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
This is so subtle I hope you can see it! Tweak at will.
Source Alexandre Naud
One more sharp little tile for you. Subtle circles this time.
Source Blunia
Sharp diamond pattern. A small 24x18px tile.
Source Tom Neal
A large pattern with funky shapes and form. An original. Sort of origami-ish.
Source Luuk van Baars
A pattern derived from repeating unit cells each derived from part of a fractal rendering in paint.net.
Source Firkin
Nicely crafted paper pattern, although a bit on the large side (500x593px).
Source Blaq Annabiosis
A cute x, if you need that sort of thing.
Source Juan Scrocchi
This is a semi-dark pattern, sort of linen-y.
Source Sagive SEO