This beige background pattern resembles a concrete wall with engravings or something similar to it.
Source V. Hartikainen
From a drawing in 'From Snowdon to the Sea. Striking stories of North and South Wales', Marie Trevelyan, 1895.
Source Firkin
Background formed from the iconic plastic construction bricks that gave me endless hours of fun when I was a lad.
Source Firkin
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
A mid-tone gray pattern with some cement looking texture.
Source Hendrik Lammers
Derived from an image that was uploaded to Pixabay by Kaz
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
The Grid. A digital frontier. I tried to picture clusters of information as they traveled through the computer.
Source Haris Šumić
A very slick dark rubber grip pattern, sort of like the grip on a camera.
Source Sinisha
It almost looks a bit blurry, but then again, so are fishes.
Source Petr Šulc
I love cream! 50x50px and lovely in all the good ways.
Source Thomas Myrman
The file was named striped lens, but hey – Translucent Fibres works too.
Source Angelica
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
From drawing in 'Musings in Maoriland', Thomas Bracken, 1890.
Source Firkin
From a drawing in 'Codogno e il suo territorio nella cronaca e nella storia'', Gio and Giarella Cairo, 1897.
Source Firkin
Smooth Polaroid pattern with a light blue tint.
Source Daniel Beaton
Background pattern originally a PNG drawn in Paint.net
Source Firkin