Not so subtle. These tileable wood patterns are very useful.
Source Elemis
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I.
Source Firkin
Washi (和紙?) is a type of paper made in Japan. Here’s the pattern for you!
Source Carolynne
From a drawing in 'Cowdray: the history of a great English House', Julia Roundell, 1884.
Source Firkin
An alternative colour scheme to the original seamless pattern.
Source Firkin
You just can’t get enough of the fabric patterns, so here is one more for your collection.
Source Krisp Designs
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
Little x’es, noise and all the stuff you like. Dark like a Monday, with a hint of blue.
Source Tom McArdle
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
A seamless background pattern with impressed gray dots.
Source V. Hartikainen
The classic notebook paper with horizontal stripes.
Source Are Sundnes
From a drawing in 'Danmarks Riges Historie af J. Steenstrup, Kr. Erslev, A. Heise, V. Mollerup, J. A. Fridericia, E. Holm, A. D. Jørgensen', 1897.
Source Firkin
Bumps, highlight and shadows – all good things.
Source Badhon Ebrahim
Remixed from a drawing in 'Some account of the Worshipful Company of Ironmongers', John Nicholl, 1866.
Source Firkin
Derived from a PNG that was uploaded to Pixabay by nutkitten
Source Firkin
Remixed from a drawing in 'Canadian forest industries July-December', 1915
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Fabric-ish patterns are close to my heart. French Stucco to the rescue.
Source Christopher Buecheler
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin