Super dark, crisp and detailed. And a Kill Bill reference.
Source Badhon Ebrahim
Here's a brown background pattern with subtle stripes. I hope you'll like the color. If not, feel free to change it using an image editor, if you know how of course. Personally, I'm using GIMP to create these backgrounds.
Source V. Hartikainen
I know there is one here already, but this is sexy!
Source Gjermund Gustavsen
Prismatic Groovy Concentric Background 4
Source GDJ
Prismatic Polyskelion Pattern No Background
Source GDJ
A simple but elegant classic. Every collection needs one of these.
Source Christopher Burton
Remixed from a drawing in 'Очерки Русской Исторіи въ памятникахъ быта', Petr Polevoi, 1879.
Source Firkin
A black tile-able background with paper-like texture.
Source V. Hartikainen
Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Derived from a PNG that was uploaded to Pixabay by nutkitten
Source Firkin
A pattern derived from repeating unit cells each derived from part of a fractal rendering in paint.net.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Crossing lines with a subtle emboss effect on a dark background.
Source Stefan Aleksić
Might not be super subtle, but quite original in its form.
Source Alex Smith
Formed from a tile based on a drawing from 'Viaggi d'un artista nell'America Meridionale', Guido Boggiani, 1895.
Source Firkin
Prismatic Abstract Geometric Background 2 No Black
Source GDJ
More bright luxury. This is a bit larger than fancy deboss, and with a bit more noise.
Source Viszt Péter
Formed by distorting a JPG from PublicDomainPictures
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
More in the paper realm, this time with fibers.
Source Jorge Fuentes
One more in the line of patterns inspired by Japanese/Asian styles. Smooth.
Source Kim Ruddock
Dark pattern with some nice diagonal stitched lines crossing over.
Source Ashton