Remixed from a drawing in 'Works. Popular edition', John Ruskin, 1886.
Source Firkin
Simple wide squares with a small indent. Fits all.
Source Petr Šulc.
A free seamless background texture of "timber wall" (colored in dark brown).
Source V. Hartikainen
Light gray grunge wall with a nice texture overlay.
Source Adam Anlauf
A beautiful dark padded pattern, like an old classic sofa.
Source Chris Baldie
Don’t look at this one too long if you’re high on something.
Source Luuk van Baars
Subtle scratches on a light gray background.
Source Andrey Ovcharov
Remixed from a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
Remixed from a raster on Pixabay, that was uploaded by ArtsyBee.
Source Firkin
Not strictly seamless in that opposite edges are not identical. But they do marry up to make an interesting pattern
Source Firkin
A black tile-able background with paper-like texture.
Source V. Hartikainen
I know there is one here already, but this is sexy!
Source Gjermund Gustavsen
Brushed aluminum, in a bright gray version. Lovely 2X as well.
Source Andre Schouten
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
Nice and simple crossed lines in dark gray tones.
Source Stefan Aleksić
Derived from a drawing in 'Historiske Afhandlinger', Adolf Jorgensen, 1898.
Source Firkin
Prismatic Abstract Geometric Background 3
Source GDJ
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
Carbon fiber is never out of fashion, so here is one more style for you.
Source Alfred Lee
Remixed from a drawing in 'Paul's Sister', Frances Peard, 1889.
Source Firkin
A new one called white wall, not by me this time.
Source Yuji Honzawa