The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
From a drawing in 'From Snowdon to the Sea. Striking stories of North and South Wales', Marie Trevelyan, 1895.
Source Firkin
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
A light gray fabric pattern with faded vertical stripes.
Source V. Hartikainen
CC0 and seamless wellington boot pattern.
Source SliverKnight
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
Medium gray pattern with small strokes to give a weave effect.
Source Catherine
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
A car pattern?! Can it be subtle? I say yes!
Source Radosław Rzepecki
This one is super crisp at 2X. Lined paper with some dust and scratches.
Source HQvectors
I guess this is inspired by the city of Ravenna in Italy and its stone walls.
Source Sentel
A seamless dark leather-like background texture with diagonal lines that look like stitches.
Source V. Hartikainen
A white version of the very popular linen pattern.
Source Ant Ekşiler
Remixed from a drawing in 'Paul's Sister', Frances Peard, 1889.
Source Firkin
Here's a subtle marble-like background for use on websites.
Source V. Hartikainen
This is a seamless pattern of a woody texture.The original image is here:https://pixabay.com/ja/users/ClassicallyPrinted-1302233/
Source Yamachem
The image a seamless pattern derived from a weed which I can't identify.The original weed image is from here:https://jp.pinterest.com/pin/500744052301423641/
Source Yamachem
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
A nice looking light gray background pattern with diagonal stripes.
Source V. Hartikainen
Paper pattern with small dust particles and 45-degree strokes.
Source Atle Mo
Inspired by a 1930s wallpaper pattern I saw on TV.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso