Crossing lines with a subtle emboss effect on a dark background.
Source Stefan Aleksić
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Prismatic Curved Diamond Pattern 7 No Background
Source GDJ
The tile this fill pattern is based on can be had by using shift+alt+i on the rectangle.
Source Firkin
A pattern drawn in Paint.net and vectorized in Vector Magic.
Source Firkin
The tile this is based on was adapted from an image that was uploaded to Pixabay by frolicsomepl. It can be had in Inkscape by selecting the rectangle and using shift+alt+i
Source Firkin
A free seamless background image with a texture of dark red "canvas". It should look very nice on web sites.
Source V. Hartikainen
A comeback for you: the popular Escheresque, now in black.
Source Patten
I guess this one is inspired by an office. A dark office.
Source Andrés Rigo.
The image is a design of blue glass.How about using it as background image?
Source Yamachem
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A beautiful dark padded pattern, like an old classic sofa.
Source Chris Baldie
Number 2 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
More Japanese-inspired patterns, Gold Scales this time.
Source Josh Green
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Super dark, crisp and detailed. And a Kill Bill reference.
Source Badhon Ebrahim
I’m guessing this is related to the Sony Vaio? It’s a nice pattern no matter where it’s from.
Source Zigzain
A large (588x375px) sand-colored pattern for your ever-growing collection. Shrink at will.
Source Alex Tapein
Prismatic Abstract Geometric Background 4 No Black
Source GDJ
Prismatic Abstract Geometric Background 2
Source GDJ
A seamless chequerboard pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin