Not the Rebel alliance, but a dark textured pattern.
Source Hendrik Lammers
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Prismatic Polka Dots Mark II 3 No Background
Source GDJ
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
Prismatic Rounded Squares Grid 4 No Background
Source GDJ
Seamless Prismatic Pythagorean Line Art Pattern No Background. A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).
Source GDJ
A light gray fabric pattern with faded vertical stripes.
Source V. Hartikainen
Remixed from a drawing in 'Analecta Eboracensia', Thomas Widdrington, 1897.
Source Firkin
There are many carbon patterns, but this one is tiny.
Source Designova
Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Lovely pattern with splattered vintage speckles.
Source David Pomfret
A cute x, if you need that sort of thing.
Source Juan Scrocchi
Lovely pattern with some good-looking non-random noise lines.
Source Zucx
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.
Source Firkin
Alternative colour scheme. 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
From a drawing in 'Uit de geschiedenis der Heilige Stede te Amsterdam', Yohannes Sterck, 1898.
Source Firkin