To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
It’s okay to be square! A nice light gray pattern with random squares.
Source Waseem Dahman
This is indeed a bit strange, but here’s to the crazy ones!
Source Christopher Buecheler
Prismatic Groovy Concentric Background 2 No Black
Source GDJ
A seamless background pattern with impressed gray dots.
Source V. Hartikainen
Black version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
Prismatic Rounded Squares Grid 4 No Background
Source GDJ
A seamless pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
A bit of scratched up grayness. Always good.
Source Dmitry
Remixed from a drawing in 'Paul's Sister', Frances Peard, 1889.
Source Firkin
After 1 comes 2, same but different. You get the idea.
Source Hendrik Lammers
Prismatic Polyskelion Pattern No Background
Source GDJ
Zero CC tileable Crackled Cement (streaks) texture, photographed and made by me. CC0
Source Sojan Janso
Prismatic Groovy Concentric Background 2
Source GDJ
Remixed from a JPG that was uploaded to Pixabay by susanlu4esm
Source Firkin
Bumps, highlight and shadows – all good things.
Source Badhon Ebrahim
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Nice and simple crossed lines in dark gray tones.
Source Stefan Aleksić
A pattern derived from part of a fractal rendering in Paint.net.
Source Firkin
Prismatic Floral Pattern 3 Variation 3 No Background
Source GDJ
Luxury pattern, looking like it came right out of Paris.
Source Daniel Beaton
Drawn in Paint.net using the kaleidoscope plug-in and vectorised.
Source Firkin