Derived from a corner decoration itself found as a jpg on Pixabay.
Source Firkin
Remixed from a drawing in 'Line and form", Walter Crane, 1914.
Source Firkin
It looks like a polished stone surface to me. Download it for free, as always.
Source V. Hartikainen
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Abstract Ellipses Background Grayscale
Source GDJ
Submitted by DomainsInfo – wtf, right? But hey, a free pattern.
Source DomainsInfo
Light gray pattern with an almost wall tile-like appearance.
Source Markus Tinner
Prismatic Abstract Geometric Background 2 No Black
Source GDJ
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A browner version of the original weathered fence texture.
Source Firkin
White fabric looking texture with some nice random wave features.
Source Hendrik Lammers
One can never have too few rice paper patterns, so here is one more.
Source Atle Mo
Dark blue concrete wall with some small dust spots.
Source Atle Mo
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
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 is indeed a bit strange, but here’s to the crazy ones!
Source Christopher Buecheler
From a design found in 'History of the Virginia Company of London; with letters to and from the first Colony, never before printed', Edward Neill, 1869.
Source Firkin
Drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
This is the third pattern called Dark Denim, but hey, we all love them!
Source Brandon Jacoby