A dark background pattern/texture of a dimpled metal plate.
Source V. Hartikainen
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Remixed from a drawing in 'A Girl in Ten Thousand', Elizabeth Meade, 1896.
Source Firkin
A seamless pattern based on a tile that can be achieved by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A seamless pattern drawn originally in Paint.net by distorting a slice of background pattern 116 and copying the resulting triangle numerous times.
Source Firkin
Fake or not, it’s quite luxurious.
Source Factorio.us Collective
Not a pattern for fabrics, but one produced from a jpg of a stack of fabric items that was posted on Pixabay. The tile that this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
ZeroCC tileable moss texture, photographed and made by me. CC0
Source Sojan Janso
Because I love dark patterns, here is Brushed Alum in a dark coating.
Source Tim Ward
A comeback for you: the popular Escheresque, now in black.
Source Patten
Hey, you never know when you’ll need a bird pattern, right?
Source Pete Fecteau
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 'Less Black than we're painted', James Payn, 1884.
Source Firkin
From drawing in 'Musings in Maoriland', Thomas Bracken, 1890.
Source Firkin
Feel free to download this "Dark Wood" background texture for your web site. The background tiles seamlessly!
Source V. Hartikainen
This is so subtle you need to bring your magnifier!
Source Carlos Valdez
One more brick pattern. A bit more depth to this one.
Source Benjamin Ward
Geometric lines are always hot, and this pattern is no exception.
Source Listvetra
Some dark 45 degree angles creating a nice pattern. Huge.
Source Dark Sharp Edges
Used correctly, this could be nice. Used in a bad way, all hell will break loose.
Source Atle Mo
The image depicts a seamless pattern which was made using stripe-like things including borders.I used OCAL cliparts called "Blue Greek Key With Lines Border" uploaded by "GR8DAN" and "daisy border" uploaded by "johnny_automatic".Thanks.
Source Yamachem
Medium gray fabric pattern with 45-degree lines going across.
Source Atle Mo
Super dark, crisp and detailed. And a Kill Bill reference.
Source Badhon Ebrahim