The original enhanced with one of Inkscapes's filters.
Source Firkin
The image depicts a seamless pattern of a tortoise in tortoiseshell (hexagon).
Source Yamachem
Just like the black maze, only in light gray. Duh.
Source Peax
Sharp diamond pattern. A small 24x18px tile.
Source Tom Neal
Just a nice looking textured pattern with faded blue stripes. Well, that's it for today... one background a day, as usual.
Source V. Hartikainen
Continuing the geometric trend, here is one more.
Source Mike Warner
Washi (和紙?) is a type of paper made in Japan. Here’s the pattern for you!
Source Carolynne
This is the remix of an OCAL clipart called "Art Nouveau ornament" uploaded by "microcosme".Thanks.This is a seamless pattern of an Art Nouveau ornament.
Source Yamachem
A free black metallic background pattern. Here's a new pattern I made that looks metallic.
Source V. Hartikainen
To get the tile this is made up from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
This is so subtle you need to bring your magnifier!
Source Carlos Valdez
Seamless Dark Grunge Texture. Here's a new grunge texture for use as a background.
Source V. Hartikainen
Light gray paper pattern with small traces of fiber and some dust.
Source Atle Mo
On a large canvas you can see it tiling, but used on smaller areas, it’s beautiful.
Source Paul Phönixweiß
This one is super crisp at 2X. Lined paper with some dust and scratches.
Source HQvectors
Produced using the clouds, flames and glass blocks plug-ins in Paint.net and the resulting .PNG vectorised with Vector Magic.
Source Firkin
This is the remix of "Background pattern 115" uploaded by "Firkin".Thanks.
Source Yamachem
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
A nice and simple gray stucco material. Great on its own, or as a base for a new pattern.
Source Bartosz Kaszubowski
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Just to prove my point, here is a slightly modified dark version.
Source Atle Mo
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin