A seamless pattern of dark bricks. Maybe it's not very realistic, but it looks good in my opinion.
Source V. Hartikainen
Remixed from a drawing that was uploaded to Pixabay by captenpub.
Source Firkin
This was formed by distorting an image of a background on Pixabay.
Source Firkin
There are many carbon patterns, but this one is tiny.
Source Designova
Classic vertical lines, in all its subtlety.
Source Cody L
A seamless pattern formed from a tile made from ornament 22. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A mid-tone gray pattern with some cement looking texture.
Source Hendrik Lammers
CC0 and seamless wellington boot pattern.
Source SliverKnight
Here's a new gray "fabric" pattern. Use it as backgrounds for websites or for other purposes.
Source V. Hartikainen
Prismatic Groovy Concentric Background 2
Source GDJ
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
From a drawing in 'Resa i Afrika, genom Angola, Ovampo och Damaraland', P. Moller, 1899.
Source Firkin
Prismatic Groovy Concentric Background 2
Source GDJ
From a drawing in 'La Principauté de Liège et les Pays-Bas au XVIe siècle', Société des Bibliophiles Liégeois ,1887.
Source Firkin
A pattern derived from repeating unit cells each derived from part of a fractal rendering in paint.net.
Source Firkin
Carbon fiber is never out of fashion, so here is one more style for you.
Source Alfred Lee
Just a nice looking textured pattern with faded blue stripes. Well, that's it for today... one background a day, as usual.
Source V. Hartikainen
From a drawing in 'Kingsdene', Maria Fetherstonehaugh, 1878.
Source Firkin
Zero CC asphalt, pavement, texture, photographed and made by me. CC0 WARNING I FOUND A SEAM ON THIS TEXTURE
Source Sojan Janso
Not a flat you live inside, like in the UK – but a flat piece of cardboard.
Source Appleshadow