A seamless pattern formed from a rectangular tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
After 1 comes 2, same but different. You get the idea.
Source Hendrik Lammers
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Remixed from a PNG that was uploaded to Pixabay by VictorianLady
Source Firkin
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
The image depicts an edo-era pattern called "same-komon" or "鮫小紋"which looks like a shark skin.The "same" in Japanese means shark in English.
Source Yamachem
A seamless pattern formed from miutopia mug remixes on a tablecloth.
Source Firkin
This makes me wanna shoot some pool! Sweet green pool table pattern.
Source Caveman
Seamless Dark Grunge Texture. Here's a new grunge texture for use as a background.
Source V. Hartikainen
Dare I call this a «flat pattern»? Probably not.
Source Dax Kieran
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
Submitted as a black pattern, I made it light and a few steps more subtle.
Source Andy
Prismatic Snowflakes Pattern No Background
Source GDJ
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A car pattern?! Can it be subtle? I say yes!
Source Radosław Rzepecki
Crossing lines with a subtle emboss effect on a dark background.
Source Stefan Aleksić
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Semi-light fabric pattern made out of random pixels in shades of gray.
Source Atle Mo
An interesting dark spotted pattern at an angle.
Source Hendrik Lammers
You don’t see many mid-tone patterns here, but this one is nice.
Source Joel Klein
One more brick pattern. A bit more depth to this one.
Source Benjamin Ward
A seamless green background texture. The image is distributed under a Creative Commons License (like all of the images here).
Source V. Hartikainen