Sharp but soft triangles in light shades of gray.
Source Pixeden
Subtle scratches on a light gray background.
Source Andrey Ovcharov
Fabric-ish patterns are close to my heart. French Stucco to the rescue.
Source Christopher Buecheler
Background Wall, Art Abstract, Star Well & CC0 texture.
Source Ractapopulous
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
A free pink background pattern.
Source V. Hartikainen
Remixed from a drawing in 'An Index to Deering's Nottinghamia Vetus et Nova', Rupert Chicken, 1899. The unit tile can be had by selecting the rectangle in Inkscape and using shift-alt-i
Source Firkin
Could be paper, could be a Polaroid frame – up to you!
Source Chaos
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
Prepared mostly as a raster in Paint.net and vectorised.
Source Firkin
Formed from decorative divider 184 in paint.net. Vectorised with Vector Magic.
Source Firkin
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
Light honeycomb pattern made up of the classic hexagon shape.
Source Federica Pelzel
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
Derived from a corner decoration itself found as a jpg on Pixabay.
Source Firkin
Bit of a strange name on this one, but still nice. Tiny gray square things.
Source Carlos Valdez
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A pattern derived from repeating unit cells each derived from part of a fractal rendering in paint.net.
Source Firkin
This is the third pattern called Dark Denim, but hey, we all love them!
Source Brandon Jacoby
A gray background pattern with a texture of textile. Suits perfectly for web design.
Source V. Hartikainen
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Formed from a tile based on a drawing from 'Viaggi d'un artista nell'America Meridionale', Guido Boggiani, 1895.
Source Firkin