Bit of a strange name on this one, but still nice. Tiny gray square things.
Source Carlos Valdez
Prismatic Groovy Concentric Background 2 No Black
Source GDJ
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
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
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
A bit like smudged paint or some sort of steel, here is scribble light.
Source Tegan Male
A seamless pattern created from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Remixed from a design on Pixabay. To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A beautiful dark wood pattern, superbly tiled.
Source Omar Alvarado
A repeating gloomy background image. This one consists of a pattern of black chains layered on top of a dark textured background.
Source V. Hartikainen
Here's an yet another seamless note paper texture for use as a background on websites.
Source V. Hartikainen
This one looks like a cork panel. Feel free to use it as a tiled background on your blog or website.
Source V. Hartikainen
A comeback for you: the popular Escheresque, now in black.
Source Patten
From a drawing in 'Heroes of North African Discovery', Nancy Meugens, 1894.
Source Firkin
Geometric triangles seem to be quite hot these days.
Source Pixeden
A bit like smudged paint or some sort of steel, here is scribble light.
Source Tegan Male