Not so subtle. These tileable wood patterns are very useful.
Source Elemis
This yellow background consists of a pattern of glossy gold buttons arranged in polka dot style on a seamless texture. Here's a pale yellow background pattern. Feel free to use it for your needs!
Source V. Hartikainen
Light gray grunge wall with a nice texture overlay.
Source Adam Anlauf
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Subtle scratches on a light gray background.
Source Andrey Ovcharov
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
Colour version of the original pattern inspired by the front cover of 'Old and New Paris', Henry Edwards, 1894.
Source Firkin
A comeback for you: the popular Escheresque, now in black.
Source Patten
The image depicts a Japanese Edo pattern called "kanoko or 鹿の子" meaning "fawn" which has a fur with small white spots.
Source Yamachem
Prismatic Groovy Concentric Background 5 No Black
Source GDJ
Prismatic Geometric Pattern Background 2
Source GDJ
Prismatic Geometric Pattern Background No Black
Source GDJ
Remixed from a raster on Pixabay, that was uploaded by ArtsyBee.
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
Seamless Prismatic Quadrilateral Line Art Pattern No Background
Source GDJ
Not a pattern for fabrics, but one produced from a jpg of a stack of fabric items that was posted on Pixabay. The tile that this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
I know there is one here already, but this is sexy!
Source Gjermund Gustavsen
This one is something special. I’d call it a flat pattern, too. Very well done, sir!
Source GetDiscount
Sometimes you just need the simplest thing.
Source Fabricio
Submitted by DomainsInfo – wtf, right? But hey, a free pattern.
Source DomainsInfo
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Retro Circles Background 7 No Black
Source GDJ
A dark one with geometric shapes and dotted lines.
Source Mohawk Studios
Formed by distorting a JPG from PublicDomainPictures
Source Firkin
You were craving more leather, so I whipped this up by scanning a leather jacket.
Source Atle Mo