Background Wall, Art Abstract, Block Well & CC0 texture.
Source Ractapopulous
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
A seamless pattern of dark bricks. Maybe it's not very realistic, but it looks good in my opinion.
Source V. Hartikainen
Very simple, very blu(e). Subtle and nice.
Source Seb Jachec
ZeroCC tileable stone texture, edited from pixabay, CC0
Source Sojan Janso
Hey, you never know when you’ll need a bird pattern, right?
Source Pete Fecteau
A repeating background of thick textured paper. Actually, it turned out to look like something between a paper and fabric.
Source V. Hartikainen
From an image on opengameart.org shared by rubberduck.
Source Firkin
This one is amazing, truly original. Go use it!
Source Viahorizon
Here's a new paper-like background for free use on personal and commercial projects (this applies to all background patterns here).
Source V. Hartikainen
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 dark brown fabric-like background texture with seamless pattern of winding stripes.
Source V. Hartikainen
A seamless dark leather-like background texture with diagonal lines that look like stitches.
Source V. Hartikainen
Traced from a drawing in 'Household Stories from the Collection of the Brothers Grimm', Wilhelm Carl Grimm , 1882.
Source Firkin
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Remixed from a drawing in 'Line and form", Walter Crane, 1914.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Abstract Tiled Background Extended 10
Source GDJ
Prismatic Geometric Pattern Background 2 No Black
Source GDJ
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Dark blue concrete wall with some small dust spots.
Source Atle Mo
There are many carbon patterns, but this one is tiny.
Source Designova
A tile-able background for websites with paper-like texture and a grid pattern layered on top of it.
Source V. Hartikainen