A comeback for you: the popular Escheresque, now in black.
Source Patten
Adapted from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
This background image has seamless texture that resembles a surface of gray stone.
Source V. Hartikainen
Fabric-ish patterns are close to my heart. French Stucco to the rescue.
Source Christopher Buecheler
Very simple, very blu(e). Subtle and nice.
Source Seb Jachec
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Retro Circles Background 8 No Black
Source GDJ
One of the few full-color patterns here, but this one was just too good to pass up.
Source Alexey Usoltsev
The tile this is based on can be retrieved by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A dark brown fabric-like background texture with seamless pattern of winding stripes.
Source V. Hartikainen
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
The tile this is based on can be retrieved by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A bit of scratched up grayness. Always good.
Source Dmitry
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
A pattern derived from repeating unit cells each derived from part of a fractal rendering in paint.net.
Source Firkin
Thin lines, noise and texture creates this crisp dark denim pattern.
Source Marco Slooten
Number 4 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Not the Rebel alliance, but a dark textured pattern.
Source Hendrik Lammers
The image depicts polka dot seamless pattern.
Source Yamachem
A seamless background pattern of dark brown wood planks.
Source V. Hartikainen
An alternative colour scheme to the original seamless pattern.
Source Firkin