Feel free to download and use it, or see the rest of the dark background patterns that I have made. Anyway, I hope you will find something that you like.
Source V. Hartikainen
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
Greyscale version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
Love me some light mesh on a Monday. Sharp.
Source Wilmotte Bastien
You know I’m a sucker for these. Well-crafted paper pattern.
Source Mihaela Hinayon
A bit strange this one, but nice at the same time.
Source Diogo Silva
Not a pattern for fabrics, but one produced from a jpg of a stack of fabric items that was posted on Pixabay. The tile that this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Inspired by a pattern seen on a public domain image of a very old tile. To get the unit cell, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Small dots with minor circles spread across to form a nice mosaic.
Source John Burks
A background tile for web with abstract repeating texture of dark "stone wall".
Source V. Hartikainen
Prismatic Groovy Concentric Background 5
Source GDJ
This seamless pattern consists of a blue grid on a yellow background.
Source V. Hartikainen
This is the remix of "Background pattern 115" uploaded by "Firkin".Thanks.
Source Yamachem
An interesting dark spotted pattern at an angle.
Source Hendrik Lammers
Remixed from a drawing in 'A Girl in Ten Thousand', Elizabeth Meade, 1896.
Source Firkin
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Zero CC tileable ground cracked, crackled, texture, made by me.
Source Sojan Janso
Washi (和紙?) is a type of paper made in Japan. Here’s the pattern for you!
Source Carolynne
From a drawing in 'Resa i Afrika, genom Angola, Ovampo och Damaraland', P. Moller, 1899.
Source Firkin
This is a hot one. Small, sharp and unique.
Source GraphicsWall
A heavy dark gray base, some subtle noise and a 45-degree grid makes this look like a pattern with a tactile feel to it.
Source Atle Mo
You just can’t get enough of the fabric patterns, so here is one more for your collection.
Source Krisp Designs