A seamless pattern based on a square tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
One more brick pattern. A bit more depth to this one.
Source Benjamin Ward
From a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
I love cream! 50x50px and lovely in all the good ways.
Source Thomas Myrman
Not a flat you live inside, like in the UK – but a flat piece of cardboard.
Source Appleshadow
This background pattern contains a seamless texture of bark. It's not very realistic, but I think it looks quite nice.
Source V. Hartikainen
Bright gray tones with a hint of some metal surface.
Source Hendrik Lammers
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
New paper pattern with a slightly organic feel to it, using some thin threads.
Source Atle Mo
Bigger is better, right? So here you have some large carbon fiber.
Source Factorio.us Collective
Prismatic Geometric Tessellation Pattern No Background
Source GDJ
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
You don’t see many mid-tone patterns here, but this one is nice.
Source Joel Klein
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Green Background Pattern
Source V. Hartikainen
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I.
Source Firkin
Pattern Background, Texture, Photoshop Structure style CC0 texture.
Source Darkmoon1968
Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
More leather, and this time it’s bigger! You know, in case you need that.
Source Elemis
From a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin
Used in small doses, this could be a nice subtle pattern. Used on a large surface, it’s dirty!
Source Paul Reulat
This is so subtle you need to bring your magnifier!
Source Carlos Valdez
By popular request, an outline version of the pentagon pattern.
Source Atle Mo