Not so subtle. These tileable wood patterns are very useful.
Source Elemis
Bright Multicolored Floral Background by Karen Arnold from PDP.
Source GDJ
More leather, and this time it’s bigger! You know, in case you need that.
Source Elemis
Used a cherry by doctormo to make this seamless pattern
Source Firkin
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
As simple and subtle as it gets. But sometimes that’s just what you want.
Source Designova
A seamless marble-like texture colored in light blue.
Source V. Hartikainen
Abstract Tiled Background Extended 6
Source GDJ
Prismatic Groovy Concentric Background 2
Source GDJ
Zero CC tileable ground (#2) cracked, crackled texture, made by me. CC0
Source Sojan Janso
You could get a bit dizzy from this one, but it might come in handy.
Source Dertig Media
Black & white version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
Inspired by a drawing in 'Kulturgeschichte', Freidrich Hellwald, 1896.
Source Firkin
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
From a design found in 'History of the Virginia Company of London; with letters to and from the first Colony, never before printed', Edward Neill, 1869.
Source Firkin
Some rectangles, a bit of dust and grunge, plus a hint of concrete.
Source Atle Mo
Sharp diamond pattern. A small 24x18px tile.
Source Tom Neal
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Can never have too many knitting patterns, especially as nice as this.
Source Victoria Spahn
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 dark striped seamless pattern suitable for use as a background on websites.
Source V. Hartikainen