A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
A seamless texture of a rough concrete surface.
Source V. Hartikainen
This was formed by distorting an image of a background on Pixabay.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A seamless pattern from a tile made from a jpg on Pixabay. To get the tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Dark Tile-able Grunge Texture. I think this texture can be classified as grunge. It's free and seamless, as always.
Source V. Hartikainen
This is sort of fresh, but still feels a bit old school.
Source Martuchox
The base gradient edited so now more details are rendered.
Source Lazur URH
Because I love dark patterns, here is Brushed Alum in a dark coating.
Source Tim Ward
From a drawing in 'Artists and Arabs', Henry Blackburn, 1868
Source Firkin
Super subtle indeed, a medium gray pattern with tiny dots in a grid.
Source Designova
Smooth Polaroid pattern with a light blue tint.
Source Daniel Beaton
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
This reminds me of Game Cube. A nice light 3D cube pattern.
Source Sander Ottens
Inspired by a pattern I saw in a 19th century book. This seamless pattern was created from a square tile. To get the tile, select the pattern in Inkscape and use shift+alt+i.
Source Firkin
Dark, square, clean and tidy. What more can you ask for?
Source Jaromír Kavan
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
To celebrate the new feature, we need some sparkling diamonds.
Source Atle Mo
Psychedelic Geometric Background No Black
Source GDJ
Prismatic Curved Diamond Pattern 8 No Background
Source GDJ
Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
A dark metallic background with a pattern of stamped dots. Here's a dark "metallic" background pattern for you.
Source V. Hartikainen
A seamless web texture of "green stone".
Source V. Hartikainen
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Zero CC tileable yellow craft paper; scanned and made by me. CC0
Source Sojan Janso