This is indeed a bit strange, but here’s to the crazy ones!
Source Christopher Buecheler
The classic subtle pattern. Sort of wall/brick looking. Or moon-looking?
Source Joel Klein
ZeroCC tileable stone texture, edited from pixabay. CC0
Source Sojan Janso
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Thin lines, noise and texture creates this crisp dark denim pattern.
Source Marco Slooten
A fun-looking elastoplast/band-aid pattern. A hint of orange tone in this one.
Source Josh Green
An alternative colour scheme for the original seamless texture formed from an image on Pixabay.
Source Firkin
Geometric lines are always hot, and this pattern is no exception.
Source Listvetra
Adapted from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Prismatic Geometric Tessellation Pattern 3 No Background
Source GDJ
Inspired by a pattern found in 'A General History of Hampshire, or the County of Southampton, including the Isle of Wight', Bernard Woodwood, 1861
Source Firkin
This is so subtle I hope you can see it! Tweak at will.
Source Alexandre Naud
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Background pattern originally a PNG drawn in Paint.net
Source Firkin
Drawn in Paint.net using the kaleidoscope plug-in and vectorised.
Source Firkin
Dark wooden pattern, given the subtle treatment. based on texture from Cloaks.
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Prismatic Hypnotic Pattern 2 No Background
Source GDJ
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Prismatic Groovy Concentric Background 3
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