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
Abstract Geometric Monochrome Pattern Prismatic No Background
Source GDJ
Little x’es, noise and all the stuff you like. Dark like a Monday, with a hint of blue.
Source Tom McArdle
Sort of reminds me of those old house wallpapers.
Source Tish
Light gray paper pattern with small traces of fiber and some dust.
Source Atle Mo
This is indeed a bit strange, but here’s to the crazy ones!
Source Christopher Buecheler
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Same as gray sand but lighter. A sandy pattern with small light dots, and some angled strokes.
Source Atle Mo
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A dark brown fabric-like background texture with seamless pattern of winding stripes.
Source V. Hartikainen
Prismatic Geometric Pattern Background
Source GDJ
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
A dark pattern made out of 3×3 circles and a 1px shadow. This works well as a carbon texture or background.
Source Atle Mo
Geometric lines are always hot, and this pattern is no exception.
Source Listvetra
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
The name is totally random, but hey, it sounds good.
Source Atle Mo
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
A free seamless texture of reptile skin colored in a dark brown color. As always, you may use it as a repeated background image in your web design works, or for any other purposes.
Source V. Hartikainen
I skipped number 3, because it wasn’t all that great. Sorry.
Source Dima Shiper