Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Not so subtle. These tileable wood patterns are very useful.
Source Elemis
Prismatic Polka Dots 3 No Background
Source GDJ
This pack of filters can help you adding a blocky overlay to objects. May come handy at drawing blocks of stone.
Source Lazur URH
Redrawn based on a drawing in 'По Сѣверо-Западу Россіи' Konstantin Sluchevsky, 1897.
Source Firkin
From a drawing in 'Handbook of the excursions proposed to be made by the Lincoln Diocesan Architectural Society, on the 27th and 28th of May, 1857', Edward Trollope, 1857.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
A seamless pattern from a tile made from a jpg on Pixabay. To get the tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
Prismatic Isometric Cube Extra Pattern No Background
Source GDJ
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
An abstract Background pattern of purple twisty patterns.
Source TikiGiki
Sort of like the back of a wooden board. Light, subtle, and stylish, just the way we like it!
Source Nikolalek
This background has abstract texture with some similarities to wood.
Source V. Hartikainen
Remixed from a drawing in 'Analecta Eboracensia', Thomas Widdrington, 1897.
Source Firkin
Abstract Arbitrary Geometric Background derived from an image on Pixabay.
Source GDJ
A pattern formed from a photograph of a 16th century ceramic tile.
Source Firkin
Abstract Ellipses Background Grayscale
Source GDJ
Clean and crisp lines all over the place. Wrap it up with this one.
Source Dax Kieran