The starting point for this was drawn on the web site steamcoded.org/PolyskelionMaker.svg
Source Firkin
This is lovely, just the right amount of subtle noise, lines and textures.
Source Richard Tabor
Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
A bit simplified version. Although it could be edited out to be simpler. Anyway, this time the tiling is converted to a pattern fill -which is using clipping for the tile's edges.
Source Lazur URH
You know I’m a sucker for these. Well-crafted paper pattern.
Source Mihaela Hinayon
Prismatic Curved Diamond Pattern 3 No Background
Source GDJ
Prismatic Groovy Concentric Background 5 No Black
Source GDJ
And some more testing, this time with Seamless Studio. It’s Robots FFS!
Source Seamless Studio
Remixed from a design on Pixabay. To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A light gray wall or floor (you decide) of concrete.
Source Atle Mo
A seamless light gray paper texture with horizontal double lines.
Source V. Hartikainen
This background has abstract texture with some similarities to wood.
Source V. Hartikainen
I’m guessing this is related to the Sony Vaio? It’s a nice pattern no matter where it’s from.
Source Zigzain
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
This beige background pattern resembles a concrete wall with engravings or something similar to it.
Source V. Hartikainen
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Colorful Floral Background 3 No Black
Source GDJ
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin