Seamless Dark Grunge Texture. Here's a new grunge texture for use as a background.
Source V. Hartikainen
Lovely pattern with some good-looking non-random noise lines.
Source Zucx
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Formed by heavily distorting part of a an image of a fish uploaded to Pixabay by GLady
Source Firkin
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A seamlessly repeating background pattern of wood. The image is procedurally generated, and, I think, it's turned out quite well.
Source V. Hartikainen
Prismatic Abstract Geometric Background 5 No Black
Source GDJ
A pattern drawn in Paint.net and vectorized in Inkscape.
Source Firkin
This is so subtle I hope you can see it! Tweak at will.
Source Alexandre Naud
Black paper texture, based on two different images.
Source Atle Mo
Based from Design Kindle
A free green background pattern with a pattern of rhombuses on a seamless texture. Feel free to use it as a tiled background image on your web site.
Source V. Hartikainen
A free light orange brown wallpaper with vertical stripes designed for use as a tiled background on websites. An yet another background pattern with vertical stripes.
Source V. Hartikainen
Prismatic Isometric Cube Extra Pattern No Background
Source GDJ
I’m not going to lie – if you submit something with the words Norwegian and Rose in it, it’s likely I’ll publish it.
Source Fredrik Scheide
Vertical lines with a bumpy, yet crisp, feel to it.
Source Raasa
A hint of orange color, and some crossed and embossed lines.
Source Adam Anlauf
The file was named striped lens, but hey – Translucent Fibres works too.
Source Angelica
Black brick wall pattern. Brick your site up!
Source Alex Parker
Prismatic Polyskelion Pattern No Background
Source GDJ
Zero CC tileable hard cover green book, scanned and made by me. CC0
Source Sojan Janso
A version without colours blended together to give a different look.
Source Firkin
Submitted in a cream color, but you know how I like it.
Source Devin Holmes
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