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
From a drawing in 'An Old Maid's Love. A Dutch tale told in English', Maarten Maartens, 1891.
Source Firkin
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Prismatic Polyskelion Pattern No Background
Source GDJ
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
The square tile 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 drawing in 'Uit de geschiedenis der Heilige Stede te Amsterdam', Yohannes Sterck, 1898.
Source Firkin
Here is a new seamless wood texture for using as blog or website backgrounds.
Source V. Hartikainen
A seamless pattern of "sewn stripes" colored in light gray.
Source V. Hartikainen
Zero CC tileable hard cover cells book texture, 4k, scanned and made by me. CC0
Source Sojan Janso
A nice one indeed, but I have a feeling we have it already? If you spot a copy, let me know on Twitter.
Source Graphiste
Inspired by a drawing in 'Kulturgeschichte', Freidrich Hellwald, 1896.
Source Firkin
Prismatic Hexagonalist Pattern No Background
Source GDJ
Sounds French. Some 3D square diagonals, that’s all you need to know.
Source Graphiste
Has nothing to do with toast, but it’s nice and subtle.
Source Pippin Lee
A new one called white wall, not by me this time.
Source Yuji Honzawa
Simple gray checkered lines, in light tones.
Source Radosław Rzepecki
Background formed from the original with an emboss effect
Source GDJ
A simple example on using clones. You can generate a nice base for a pattern fill quickly with it.
Source Lazur URH
A seamless pattern created from a square tile. To get the tile, select the pattern in Inkscape and use shift+alt+i.
Source Firkin
Prismatic Polka Dots Mark II No Background
Source GDJ
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
Farmer could be some sort of fabric pattern, with a hint of green.
Source Fabian Schultz
From a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin
There are many carbon patterns, but this one is tiny.
Source Designova