Here's a dark background pattern that contains a steel grid pattern as a texture. Use it as a website background or for other purposes. It's free!
Source V. Hartikainen
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
Based on an image that was uploaded to Pixabay by devanath
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Simple combination of stripy squares with their negatively coloured counterparts
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
A seamless pattern created from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
One more brick pattern. A bit more depth to this one.
Source Benjamin Ward
You know you love wood patterns, so here’s one more.
Source Richard Tabor
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Love the style on this one, very fresh. Diagonal diamond pattern. Get it?
Source INS
In the spirit of WWDC 2011, here is a dark iOS inspired linen pattern.
Source Atle Mo
Crossing lines with a subtle emboss effect on a dark background.
Source Stefan Aleksić
Sort of like the back of a wooden board. Light, subtle, and stylish, just the way we like it!
Source Nikolalek
Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
Prismatic Curved Diamond Pattern 8 No Background
Source GDJ
This is a semi-dark pattern, sort of linen-y.
Source Sagive SEO
Prismatic Geometric Pattern Background 2 No Black
Source GDJ
This background pattern looks like bamboo to me. Feel free to download it for your website (for your blog perhaps?).
Source V. Hartikainen
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
CC0 remixed from a drawing. Walter Crane, 1914, Firkin.
Source SliverKnight
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Derived from a corner decoration itself found as a jpg on Pixabay.
Source Firkin
Prismatic Geometric Pattern Background 2
Source GDJ