Looks a bit like concrete with subtle specks spread around the pattern.
Source Mladjan Antic
Clean and crisp lines all over the place. Wrap it up with this one.
Source Dax Kieran
Alternative colour scheme. 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
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Dark, crisp and subtle. Tiny black lines on top of some noise.
Source Wilmotte Bastien
It has waves, so make sure you don’t get sea sickness.
Source CoolPatterns
Colour version that is close to the original drawing uploaded to Pixabay by pencilparker.
Source Firkin
A large pattern with funky shapes and form. An original. Sort of origami-ish.
Source Luuk van Baars
A background tile of dark textile. Made this a long time ago and just now decided to publish it.
Source V. Hartikainen
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
Bigger is better, right? So here you have some large carbon fiber.
Source Factorio.us Collective
A free black metallic background pattern. Here's a new pattern I made that looks metallic.
Source V. Hartikainen
Prismatic Geometric Tessellation Pattern No Background
Source GDJ
A seamless pattern created from a square tile. To get the tile, select the pattern in Inkscape and use shift+alt+i.
Source Firkin
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
Smooth Polaroid pattern with a light blue tint.
Source Daniel Beaton
From an image on opengameart.org shared by rubberduck.
Source Firkin
White circles connecting on a light gray background.
Source Mark Collins
Zero CC tillable hard cover red book with X shape marks. Scanned and made by me.
Source Sojan Janso
Carbon fiber is never out of fashion, so here is one more style for you.
Source Alfred Lee
A heavy dark gray base, some subtle noise and a 45-degree grid makes this look like a pattern with a tactile feel to it.
Source Atle Mo
With a name this awesome, how can I go wrong?
Source Nikolay Boltachev
From a drawing of the coat of arms of the Ottoman Empire on Wikimedia.
Source Firkin
As simple and subtle as it gets. But sometimes that’s just what you want.
Source Designova