Not so subtle. These tileable wood patterns are very useful.
Source Elemis
Prismatic Geometric Pattern Background
Source GDJ
From a drawing in 'Uit de geschiedenis der Heilige Stede te Amsterdam', Yohannes Sterck, 1898.
Source Firkin
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
A pattern formed from a squared tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.
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
The image depicts a seamless pattern of Japanese Edo pattern called "kikkou-matsu" or "亀甲松" meaning " tortoiseshell-pinetree".The real pinetree is like this: https://jp.pinterest.com/pin/500744052301065077/
Source Yamachem
It’s like Shine Dotted’s sister, only rotated 45 degrees.
Source mediumidee
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
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Prismatic Curved Diamond Pattern 6 No Background
Source GDJ
From a drawing in 'Gately's World's Progress', Charles Beale, 1886.
Source Firkin
A subtle shadowed checkered pattern. Increase the lightness for even more subtle sexiness.
Source Josh Green
Snap! It’s a pattern, and it’s not grayscale! Of course you can always change the color in Photoshop.
Source Atle Mo
A free black metallic background pattern. Here's a new pattern I made that looks metallic.
Source V. Hartikainen
A free pink background pattern.
Source V. Hartikainen
Colour version of the original pattern inspired by the front cover of 'Old and New Paris', Henry Edwards, 1894.
Source Firkin
Retro Circles Background 8 No Black
Source GDJ
From a drawing in 'Royal Ramsgate', James Simson, 1897.
Source Firkin
Real snow that tiles, not easy. This is not perfect, but an attempt.
Source Atle Mo
Remixed from a drawing in 'The Canadian horticulturist', 1892
Source Firkin