Not so subtle. These tileable wood patterns are very useful.
Source Elemis
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
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
ZeroCC tileable stone texture, edited from pixabay. CC0
Source Sojan Janso
Just what the name says, paper fibers. Always good to have.
Source Heliodor jalba
The image is a remix of "edo pattern-samekomon".I changed the color of dots from black to white and added BG in light-brown.
Source Yamachem
Formed from a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Just like your old suit, all striped and smooth.
Source Alex Berkowitz
The image depicts a seamless pattern of the design which includes a stylized lotus and a stylized crane.I referred to the original image in a book which is into public domain.
Source Yamachem
Small dots with minor circles spread across to form a nice mosaic.
Source John Burks
A seamless pattern formed from a modified version of rwwgub's tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
ZeroCC tileable stone texture, edited from pixabay. CC0
Source Sojan Janso
Otis Ray Redding was an American soul singer-songwriter, record producer, arranger, and talent scout. So you know.
Source Thomas Myrman
Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
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
A light brushed aluminum pattern for your pleasure.
Source Tim Ward
Tiny little fibers making a soft and sweet look.
Source Badhon Ebrahim
Derived from a drawing in 'Historiske Afhandlinger', Adolf Jorgensen, 1898.
Source Firkin
You know you love wood patterns, so here’s one more.
Source Richard Tabor
The basic shapes never get old. Simple triangle pattern.
Source Atle Mo
Super dark, crisp and detailed. And a Kill Bill reference.
Source Badhon Ebrahim
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Prismatic Basic Pattern 2 No Background
Source GDJ
Seamless pattern inspired by a drawing on Pixabay. To get the tile this is formed from, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A series of 5 patterns. That’s what the P stands for, if you didn’t guess it.
Source Dima Shiper