Some more diagonal lines and noise, because you know you want it.
Source Atle Mo
A free seamless background with pink spots.
Source V. Hartikainen
Dark Tile-able Grunge Texture. I think this texture can be classified as grunge. It's free and seamless, as always.
Source V. Hartikainen
A seamlessly tileable pink background texture.
Source V. Hartikainen
Remixed from a drawing that was uploaded to Pixabay by ractapopulous
Source Firkin
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Fake or not, it’s quite luxurious.
Source Factorio.us Collective
A free tileable background colored in off-white (antique white) color.
Source V. Hartikainen
Prismatic Curved Diamond Pattern 4 No Background
Source GDJ
Not so subtle. These tileable wood patterns are very useful.
Source Elemis
Light gray version of the Binding pattern that looks a bit like fabric.
Source Newbury
Here's a new gray "fabric" pattern. Use it as backgrounds for websites or for other purposes.
Source V. Hartikainen
Prismatic Polka Dots Mark II 2 No Background
Source GDJ
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Same as the black version, but now in shades of gray. Very subtle and fine grained.
Source Atle Mo
From a drawing in 'Cowdray: the history of a great English House', Julia Roundell, 1884.
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 was formed by distorting an image of a background on Pixabay.
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 brown seamless wood texture in a form of stripe pattern. The result has turned out pretty well, in my opinion.
Source V. Hartikainen
Prismatic Hexagonalist Pattern No Background
Source GDJ