White circles connecting on a light gray background.
Source Mark Collins
A repeating background of thick textured paper. Actually, it turned out to look like something between a paper and fabric.
Source V. Hartikainen
One can never have too few rice paper patterns, so here is one more.
Source Atle Mo
From a drawing in 'Heroes of North African Discovery', Nancy Meugens, 1894.
Source Firkin
Prismatic Geometric Pattern Background No Black
Source GDJ
Remixed from a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Number five from the same submitter, makes my job easy.
Source Dima Shiper
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
Here's a seamless brown cork board background texture. Feel free to download or reshare if you like.
Source V. Hartikainen
Remixed from a JPG that was uploaded to Pixabay by Osckar
Source Firkin
Sharp diamond pattern. A small 24x18px tile.
Source Tom Neal
Background formed from the iconic plastic construction bricks that gave me endless hours of fun when I was a lad.
Source Firkin
Bright gray tones with a hint of some metal surface.
Source Hendrik Lammers
Background Wall, Art Abstract, Block Well & CC0 texture.
Source Ractapopulous
It’s okay to be square! A nice light gray pattern with random squares.
Source Waseem Dahman
A large pattern with funky shapes and form. An original. Sort of origami-ish.
Source Luuk van Baars
Abstract Geometric Monochrome Pattern Prismatic No Background
Source GDJ
Just like your old suit, all striped and smooth.
Source Alex Berkowitz
A seamless dark leather-like background texture with diagonal lines that look like stitches.
Source V. Hartikainen
Remixed from a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Prismatic Geometric Pattern Background
Source GDJ
Prismatic Abstract Geometric Background 5
Source GDJ
From a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
Prismatic Polka Dots Mark II No Background
Source GDJ
A light gray fabric pattern with faded vertical stripes.
Source V. Hartikainen
A dark gray, sandy pattern with small light dots, and some angled strokes.
Source Atle Mo
Square design drawn in Paint.net and vectorized in Vector Magic.
Source Firkin