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
Tile available in Inkscape using shift-alt-i on the selected rectangle
Source Firkin
A criss-cross pattern similar to one I saw mown into a sports field.
Source Firkin
Square design drawn in Paint.net and vectorized in Vector Magic.
Source Firkin
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
This is indeed a bit strange, but here’s to the crazy ones!
Source Christopher Buecheler
One more brick pattern. A bit more depth to this one.
Source Benjamin Ward
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Pattern Background, Texture, Photoshop Structure style CC0 texture.
Source Darkmoon1968
Lovely pattern with some good-looking non-random noise lines.
Source Zucx
Prismatic Polka Dots Mark II No Background
Source GDJ
From a drawing in 'Cassell's Library of English Literature', Henry Morley, 1883.
Source Firkin
That’s what it is, a dark dot. Or sort of carbon looking.
Source Tsvetelin Nikolov
A seamless web texture with illustration of pale color stains on canvas.
Source V. Hartikainen
Carbon fiber is never out of fashion, so here is one more style for you.
Source Alfred Lee
Oh yes, it happened! A pattern in full color.
Source Atle Mo
Drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
A simple circle. That’s all it takes. This one is even transparent, for those who like that.
Source Saqib
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
Dark pattern with some nice diagonal stitched lines crossing over.
Source Ashton