Not the Rebel alliance, but a dark textured pattern.
Source Hendrik Lammers
Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Light gray paper pattern with small traces of fiber and some dust.
Source Atle Mo
You may use it as is, or modify it as you like.
Source V. Hartikainen
Prismatic Groovy Concentric Background 4
Source GDJ
A pattern formed from a squared tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
From a drawing in 'The Quiver of Love', Walter Crane, 1876
Source Firkin
Simple gray checkered lines, in light tones.
Source Radosław Rzepecki
Prismatic Groovy Concentric Background No Black
Source GDJ
The name alone is awesome, but so is this sweet dark pattern.
Source Federica Pelzel
Prismatic Triangular Background Design Mark II 5
Source GDJ
Remixed from a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
This pack of filters can help you adding a blocky overlay to objects. May come handy at drawing blocks of stone.
Source Lazur URH
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
The following orange background pattern resembles a honeycomb.
Source V. Hartikainen
Pattern produced in Paint.net using the Vibrato plug-in.
Source Firkin
A seamlessly repeating background pattern of wood. The image is procedurally generated, and, I think, it's turned out quite well.
Source V. Hartikainen
Awesome name, great pattern. Who does not love space?
Source Nick Batchelor
Number 5 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
A mid-tone gray pattern with some cement looking texture.
Source Hendrik Lammers
Imagine you zoomed in 1000X on some fabric. But then it turned out to be a skeleton!
Source Angelica