Not so subtle. These tileable wood patterns are very useful.
Source Elemis
Tile-able Dark Brown Wood Background. Feel free to use it as a background image in your designs or somewhere on the web. By the way, the color seems to be close to Coffee Brown.
Source V. Hartikainen
Derived from a corner decoration itself found as a jpg on Pixabay.
Source Firkin
A seamless pattern drawn originally in Paint.net by distorting a slice of background pattern 116 and copying the resulting triangle numerous times.
Source Firkin
A bit like some carbon, or knitted netting if you will.
Source Anna Litvinuk
Can’t believe we don’t have this in the collection already! Slick woven pattern with crisp details.
Source Max Rudberg
Background pattern made in "Grunge-Like" style. Available in both SVG and JPG formats. Edit to your needs then click the download button.
Source V. Hartikainen
Super subtle indeed, a medium gray pattern with tiny dots in a grid.
Source Designova
8 by 8 pixels, and just what the title says.
Source pixilated
He influenced us all. “Don’t be sad because it’s over. Smile because it happened.”
Source Atle Mo
Prismatic Abstract Line Art Pattern Background 2
Source GDJ
Floral patterns will never go out of style, so enjoy this one.
Source Lasma
I skipped number 3, because it wasn’t all that great. Sorry.
Source Dima Shiper
This ons is quite old school looking. Retro, even. I like it.
Source Arno Declercq
Awesome name, great pattern. Who does not love space?
Source Nick Batchelor
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A seamless pattern formed from a square tile based on a jpg on Pixabay. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I.
Source Firkin
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857. The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Remixed from a drawing in 'The March of Loyalty', Letitia MacClintock, 1884.
Source Firkin