Some more diagonal lines and noise, because you know you want it.
Source Atle Mo
Paper pattern with small dust particles and 45-degree strokes.
Source Atle Mo
An interesting dark spotted pattern at an angle.
Source Hendrik Lammers
Almost like little fish shells, or dragon skin.
Source Graphiste
A seamlessly repeating background pattern of wood. The image is procedurally generated, and, I think, it's turned out quite well.
Source V. Hartikainen
Like the name says, light and gray, with some small dots and circles.
Source Brenda Lay
Medium gray fabric pattern with 45-degree lines going across.
Source Atle Mo
A seamless pattern formed from miutopia's cakes on a tablecloth.
Source Firkin
Remixed from a raster on Pixabay that was uploaded by ArtsyBee.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A seamless striped fabric-like texture colored in a dark reddish brown color.
Source V. Hartikainen
Black brick wall pattern. Brick your site up!
Source Alex Parker
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
Here I have tried to create something that would look like maple wood. Not sure how well it's turned out, but at least it looks like wood.
Source V. Hartikainen
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
A light gray fabric pattern with faded vertical stripes.
Source V. Hartikainen
A seamless pattern of leopard skin. It should look nice as a background element on web pages.
Source V. Hartikainen
Prismatic Rounded Squares Grid 4 No Background
Source GDJ
New paper pattern with a slightly organic feel to it, using some thin threads.
Source Atle Mo
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
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
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin