Dark and hard, just the way we like it. Embossed triangles makes a nice pattern.
Source Ivan Ginev
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
A seamless pattern created from a square tile. To get the tile, select the pattern in Inkscape and use shift+alt+i.
Source Firkin
Zero CC tileable dry grass texture, photographed and made by me. CC0
Source Sojan Janso
He influenced us all. “Don’t be sad because it’s over. Smile because it happened.”
Source Atle Mo
People seem to enjoy dark patterns, so here is one with some circles.
Source Atle Mo
This is a semi-dark pattern, sort of linen-y.
Source Sagive SEO
Light gray pattern with an almost wall tile-like appearance.
Source Markus Tinner
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
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
Black version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
Dark pattern with some nice diagonal stitched lines crossing over.
Source Ashton
From a drawing in 'Friend or Fortune? The story of a strange year', Robert Overton, 1897.
Source Firkin
From a drawing of the coat of arms of the Ottoman Empire on Wikimedia.
Source Firkin
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
A seamless green background texture. The image is distributed under a Creative Commons License (like all of the images here).
Source V. Hartikainen
Abstract Geometric Monochrome Pattern Prismatic No Background
Source GDJ
From a drawing in 'Cassell's Library of English Literature', Henry Morley, 1883.
Source Firkin
Same as Silver Scales, but in black. Turn your site into a dragon with this great scale pattern.
Source Alex Parker
Prismatic Hypnotic Pattern No Background
Source GDJ
A car pattern?! Can it be subtle? I say yes!
Source Radosław Rzepecki
Prismatic Abstract Geometric Background 2
Source GDJ