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 free background image with a seamless texture of cardboard. This texture of cardboard looks quite realistic, especially when is actually tiled.
Source V. Hartikainen
A nice and simple white rotated tile pattern.
Source Another One
Remixed from a PNG that was uploaded to Pixabay by VictorianLady
Source Firkin
Not even 1kb, but very stylish. Gray thin lines.
Source Struck Axiom
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
A simple circle. That’s all it takes. This one is even transparent, for those who like that.
Source Saqib
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 new take on the black linen pattern. Softer this time.
Source Atle Mo
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
A grayscale fabric pattern with vertical lines of stitch holes.
Source V. Hartikainen
A slightly more textured pattern, medium gray. A bit like a potato sack?
Source Bilal Ketab
A heavy hitter at 400x400px, but lovely still.
Source Breezi
It looks like a polished stone surface to me. Download it for free, as always.
Source V. Hartikainen
Prismatic Polka Dots Mark II 2 No Background
Source GDJ
Prismatic Polka Dots Mark II 3 No Background
Source GDJ
A series of 5 patterns. That’s what the P stands for, if you didn’t guess it.
Source Dima Shiper
Medium gray fabric pattern with 45-degree lines going across.
Source Atle Mo
Derived from an image that was uploaded to Pixabay by mdmelo.
Source Firkin
Prismatic Floral Background No Black
Source GDJ