Scanned some rice paper and tiled it up for you. Enjoy.
Source Atle Mo
A repeating gloomy background image. This one consists of a pattern of black chains layered on top of a dark textured background.
Source V. Hartikainen
Might not be super subtle, but quite original in its form.
Source Alex Smith
A dark pattern made out of 3×3 circles and a 1px shadow. This works well as a carbon texture or background.
Source Atle Mo
This is the remix of an OCAL clipart called "Art Nouveau ornament" uploaded by "microcosme".Thanks.This is a seamless pattern of an Art Nouveau ornament.
Source Yamachem
Background Wall, Art Abstract, Watercolor Vintage style CC0 texture.
Source Ractapopulous
An interesting dark spotted pattern at an angle.
Source Hendrik Lammers
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
A bit strange this one, but nice at the same time.
Source Diogo Silva
Prismatic Chevrons Pattern 5 With Background
Source GDJ
A background pattern with blue on white vertical stripes.
Source V. Hartikainen
Nicely crafted paper pattern, although a bit on the large side (500x593px).
Source Blaq Annabiosis
A seamless pattern recreated from an image on Pixabay. It is reminiscent of parquet flooring and is formed from a square tile, which can be recovered in Inkscape by selecting the ungrouped rectangle and using shift-alt-I together.
Source Firkin
Prismatic Curved Diamond Pattern 2 No Background
Source GDJ
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
I know there is one here already, but this is sexy!
Source Gjermund Gustavsen
Prismatic Snowflakes Pattern No Background
Source GDJ
A free black metallic background pattern. Here's a new pattern I made that looks metallic.
Source V. Hartikainen
Looks like an old wall. I guess that’s it then?
Source Viahorizon
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin