Drawn in Paint.net using the kaleidoscope plug-in and vectorised.
Source Firkin
Original minus the background
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
A seamless pattern formed from a tile made from page ornament 22. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
High detail stone wall with minor cracks and specks.
Source Projecteightyfive
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Could remind you a bit of those squares in Super Mario Bros, yeh?
Source Jeff Wall
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Abstract Ellipses Background Grayscale
Source GDJ
A bit strange this one, but nice at the same time.
Source Diogo Silva
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Tiny little flowers growing on your screen. Nice, huh?
Source Themes Tube
Not strictly seamless in that opposite edges are not identical. But they do marry up to make an interesting pattern
Source Firkin
This pack of filters can help you adding a blocky overlay to objects. May come handy at drawing blocks of stone.
Source Lazur URH
This is the third pattern called Dark Denim, but hey, we all love them!
Source Brandon Jacoby
A repeatable image with dark background and metal grid pattern.
Source V. Hartikainen
Remixed from a drawing in 'Some account of the Worshipful Company of Ironmongers', John Nicholl, 1866.
Source Firkin