The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
From a design found in 'History of the Virginia Company of London; with letters to and from the first Colony, never before printed', Edward Neill, 1869.
Source Firkin
We have some linen patterns here, but none that are stressed. Until now.
Source Jordan Pittman
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
Dare I call this a «flat pattern»? Probably not.
Source Dax Kieran
Semi-light fabric pattern made out of random pixels in shades of gray.
Source Atle Mo
Fabric-ish patterns are close to my heart. French Stucco to the rescue.
Source Christopher Buecheler
Geometric triangles seem to be quite hot these days.
Source Pixeden
Prismatic Curved Diamond Pattern 4 No Background
Source GDJ
Background Wall, Art Abstract, Block Well & CC0 texture.
Source Ractapopulous
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Formed from a tile based on a drawing from 'Viaggi d'un artista nell'America Meridionale', Guido Boggiani, 1895.
Source Firkin
Has nothing to do with toast, but it’s nice and subtle.
Source Pippin Lee
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Vertical lines with a bumpy, yet crisp, feel to it.
Source Raasa
Smooth Polaroid pattern with a light blue tint.
Source Daniel Beaton
This is a semi-dark pattern, sort of linen-y.
Source Sagive SEO
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
Not so subtle. These tileable wood patterns are very useful.
Source Elemis
Light gray grunge wall with a nice texture overlay.
Source Adam Anlauf
White fabric looking texture with some nice random wave features.
Source Hendrik Lammers
A seamless web background with texture of aged grid paper.
Source V. Hartikainen
Washi (和紙?) is a type of paper made in Japan. Here’s the pattern for you!
Source Carolynne