A seamless pattern formed from a sports car on clker.com. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
From a drawing in 'From Snowdon to the Sea. Striking stories of North and South Wales', Marie Trevelyan, 1895.
Source Firkin
This is so subtle: We’re talking 1% opacity. Get your squint on!
Source Atle Mo
The tile this is based on can be retrieved by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Some more diagonal lines and noise, because you know you want it.
Source Atle Mo
Greyscale version of a pattern that came out of playing with the 'slinky' plug-in for Paint.net
Source Firkin
From a drawing in 'Artists and Arabs', Henry Blackburn, 1868
Source Firkin
This seamless web background texture looks like gray stone. It's great for using as a background image on web pages, or on some of their elements. Anyway, I hope you will find use for it.
Source V. Hartikainen
A comeback for you: the popular Escheresque, now in black.
Source Patten
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Vector version of a JPG that was uploaded to Pixabay by theasad121
Source Firkin
Remixed from a drawing that was uploaded to Pixabay by DavidZydd
Source Firkin
Simple combination of stripy squares with their negatively coloured counterparts
Source Firkin
A very dark spotted twinkle pattern for your twinkle needs.
Source Badhon Ebrahim
Formed from a tile based on a drawing from 'Viaggi d'un artista nell'America Meridionale', Guido Boggiani, 1895.
Source Firkin
A hint of orange color, and some crossed and embossed lines.
Source Adam Anlauf
This is indeed a bit strange, but here’s to the crazy ones!
Source Christopher Buecheler
A seamless green background texture. The image is distributed under a Creative Commons License (like all of the images here).
Source V. Hartikainen
If you like it a bit trippy, this wave pattern might be for you.
Source Ian Soper
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso