From a drawing in 'Gately's World's Progress', Charles Beale, 1886.
Source Firkin
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Looks like an old wall. I guess that’s it then?
Source Viahorizon
Prismatic Abstract Geometric Background 4 No Black
Source GDJ
This is indeed a bit strange, but here’s to the crazy ones!
Source Christopher Buecheler
Remixed from a JPG that was uploaded to Pixabay by Osckar
Source Firkin
This is the remix of "Background pattern 115" uploaded by "Firkin".Thanks.
Source Yamachem
Light gray grunge wall with a nice texture overlay.
Source Adam Anlauf
A slightly more textured pattern, medium gray. A bit like a potato sack?
Source Bilal Ketab
Zero CC asphalt, pavement, texture, photographed and made by me. CC0 WARNING I FOUND A SEAM ON THIS TEXTURE
Source Sojan Janso
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
A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).
Source GDJ
This reminds me of Game Cube. A nice light 3D cube pattern.
Source Sander Ottens
Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Tiny, tiny 3D cubes. Reminds me of the good old pattern from k10k.
Source Etienne Rallion
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin