If you like it a bit trippy, this wave pattern might be for you.
Source Ian Soper
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Prismatic Abstract Line Art Pattern Background
Source GDJ
From a drawing in 'Royal Ramsgate', James Simson, 1897.
Source Firkin
A seamless chequerboard pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i. Alternative colour scheme.
Source Firkin
This is indeed a bit strange, but here’s to the crazy ones!
Source Christopher Buecheler
It almost looks a bit blurry, but then again, so are fishes.
Source Petr Šulc
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
Prismatic Hypnotic Pattern No Background
Source GDJ
Prismatic Isometric Cube Wireframe Pattern No Background
Source GDJ
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
ZeroCC tileable beechwood wood texture, generated in Neo Texture Edit by me. CC0
Source Sojan Janso
Inspired by a JPG that was uploaded to Pixabay by kokon_art
Source Firkin
This was formed by distorting an image of a background on Pixabay.
Source Firkin
Might not be super subtle, but quite original in its form.
Source Alex Smith
Simple wide squares with a small indent. Fits all.
Source Petr Šulc.
The tile this is formed from can be retrieved in Inkscape by selecting the rectangle and using shift+alt+i
Source Firkin
Original minus the background
Source Firkin
First pattern tailor-made for Retina, with many more to come. All the old ones are upscaled, in case you want to re-download.
Source Atle Mo
Remixed from a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
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 'The Quiver of Love', Walter Crane, 1876
Source Firkin
Dark, square, clean and tidy. What more can you ask for?
Source Jaromír Kavan
The edges of all the red objects line up either vertically or horizontally, but it doesn't appear so. Made from a square tile that can be got by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin