Not so subtle. These tileable wood patterns are very useful.
Source Elemis
Lovely pattern with splattered vintage speckles.
Source David Pomfret
A seamless pattern formed from miutopia's cakes on a tablecloth.
Source Firkin
From a drawing in 'Cassell's Library of English Literature', Henry Morley, 1883.
Source Firkin
Not the Rebel alliance, but a dark textured pattern.
Source Hendrik Lammers
Background formed from the iconic plastic construction bricks that gave me endless hours of fun when I was a lad.
Source Firkin
Abstract Tiled Background Extended 10
Source GDJ
A floral background formed from numerous clones of flower 117.
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
Lovely light gray floral motif with some subtle shades.
Source GraphicsWall
An abstract texture of water. It's not perfect, but will do. You may download if you like it.
Source V. Hartikainen
A free seamless background with pink spots.
Source V. Hartikainen
It’s okay to be square! A nice light gray pattern with random squares.
Source Waseem Dahman
That’s what it is, a dark dot. Or sort of carbon looking.
Source Tsvetelin Nikolov
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin
The basic shapes never get old. Simple triangle pattern.
Source Atle Mo
Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A slightly more textured pattern, medium gray. A bit like a potato sack?
Source Bilal Ketab
Colorful Floral Background 3 No Black
Source GDJ
I scanned a paper coffee cup. You know, in case you need it.
Source Atle Mo
Alternative colour scheme. 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