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
Not a flat you live inside, like in the UK – but a flat piece of cardboard.
Source Appleshadow
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
The file was named striped lens, but hey – Translucent Fibres works too.
Source Angelica
A seamless pattern with wide vertical stripes colored in pale yellow.
Source V. Hartikainen
From a drawing in 'Cowdray: the history of a great English House', Julia Roundell, 1884.
Source Firkin
Geometric triangles seem to be quite hot these days.
Source Pixeden
Could be paper, could be a Polaroid frame – up to you!
Source Chaos
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Bumps, highlight and shadows – all good things.
Source Badhon Ebrahim
Prismatic Polyskelion Pattern No Background
Source GDJ
A slightly more textured pattern, medium gray. A bit like a potato sack?
Source Bilal Ketab
Tweed is back in style – you heard it here first. Also, the @2X version here is great!
Source Simon Leo
This one could be the shirt of a golf player. Angled lines in different thicknesses.
Source Olivier Pineda
A version without colours blended together to give a different look.
Source Firkin
The image depicts a seamless pattern of a fishnet with a plenty of fish.It may be a lucky charm for fishermen.
Source Yamachem