Just to prove my point, here is a slightly modified dark version.
Source Atle Mo
Inspired by a pattern found in 'A General History of Hampshire, or the County of Southampton, including the Isle of Wight', Bernard Woodwood, 1861
Source Firkin
A bit like smudged paint or some sort of steel, here is scribble light.
Source Tegan Male
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 brick wall pattern. Brick your site up!
Source Alex Parker
From a design found in 'History of the Virginia Company of London; with letters to and from the first Colony, never before printed', Edward Neill, 1869.
Source Firkin
To get the tile this is based on, 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
Thin lines, noise and texture creates this crisp dark denim pattern.
Source Marco Slooten
Super detailed 16×16 tile that forms a beautiful pattern of straws.
Source Pavel
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A light brushed aluminum pattern for your pleasure.
Source Tim Ward
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Super simple but very nice indeed. Gray with vertical stripes.
Source Merrin Macleod
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
First pattern tailor-made for Retina, with many more to come. All the old ones are upscaled, in case you want to re-download.
Source Atle Mo
From a drawing in 'Resa i Afrika, genom Angola, Ovampo och Damaraland', P. Moller, 1899.
Source Firkin
White fabric looking texture with some nice random wave features.
Source Hendrik Lammers
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Same as Silver Scales, but in black. Turn your site into a dragon with this great scale pattern.
Source Alex Parker
A seamless tessellation pattern. To get the tile this is formed from, select the pattern in Inkscape and use shift+alt+i.
Source Firkin
Bumps, highlight and shadows – all good things.
Source Badhon Ebrahim
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I.
Source Firkin
The tile can be had by using shift+alt+i on the selected rectangle in Inkscape
Source Firkin
Utilising a bird from s-light and some flowers from Almeidah. To get the unit 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
Drawn in Paint.net and vectorised in Vector Magic
Source Firkin