Because I love dark patterns, here is Brushed Alum in a dark coating.
Source Tim Ward
Formed by distorting a JPG from PublicDomainPictures
Source Firkin
This is a semi-dark pattern, sort of linen-y.
Source Sagive SEO
Snap! It’s a pattern, and it’s not grayscale! Of course you can always change the color in Photoshop.
Source Atle Mo
Not even 1kb, but very stylish. Gray thin lines.
Source Struck Axiom
This light blue background pattern is quite pleasing to the eye, it consists of a tiny rough grid pattern, which is seamless by design. That's it, if you like the color, you can use this seamless pattern in a web design without making any further modifications to it.
Source V. Hartikainen
Seamless Background For Websites. It has a texture similar to cork-board.
Source V. Hartikainen
Small dots with minor circles spread across to form a nice mosaic.
Source John Burks
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 background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.
Source Firkin
This seamless light brown background texture resembles a wallpaper with vertical stripes. One way to use it is as a tiled background on web sites.
Source V. Hartikainen
From a drawing in 'Resa i Afrika, genom Angola, Ovampo och Damaraland', P. Moller, 1899.
Source Firkin
Background Wall, Art Abstract, Block Well & CC0 texture.
Source Ractapopulous
A pattern derived from repeating unit cells each derived from part of a fractal rendering in paint.net.
Source Firkin
Prismatic Isometric Cube Wireframe Pattern No Background
Source GDJ
Here's a new gray "fabric" pattern. Use it as backgrounds for websites or for other purposes.
Source V. Hartikainen
It’s an egg, in the form of a pattern. This really is 2012.
Source Paul Phönixweiß
The image depicts a seamless pattern which was made using stripe-like things including borders.I used OCAL cliparts called "Blue Greek Key With Lines Border" uploaded by "GR8DAN" and "daisy border" uploaded by "johnny_automatic".Thanks.
Source Yamachem
Prismatic Curved Diamond Pattern 3 No Background
Source GDJ