You don’t see many mid-tone patterns here, but this one is nice.
Source Joel Klein
Derived from elements found in a floral ornament drawing on Pixabay.
Source Firkin
Background Wall, Art Abstract, Blue Well & CC0 texture.
Source Ractapopulous
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 seamless pattern of leopard skin. It should look nice as a background element on web pages.
Source V. Hartikainen
Drawn in Paint.net using the kaleidoscope plug-in and vectorised.
Source Firkin
Inspired by a pattern I saw in a 19th century book. This seamless pattern was created from a square tile. To get the tile, select the pattern in Inkscape and use shift+alt+i.
Source Firkin
The original enhanced with one of Inkscapes's filters.
Source Firkin
A seamlessly tile-able grunge background image.
Source V. Hartikainen
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
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A background formed from an image of an old tile on the New York Metropolitan Museum of Art website. To get the base tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
I love cream! 50x50px and lovely in all the good ways.
Source Thomas Myrman
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A colourful background drawn originally in paint.net and vectorised in Vector Magic.
Source Firkin
A seamless pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Heavy depth and shadows here, but might work well on some mobile apps.
Source Damian Rivas
Wild Oliva or Oliva Wilde? Darker than the others, sort of a medium dark pattern.
Source Badhon Ebrahim
Remixed from a drawing in 'Analecta Eboracensia', Thomas Widdrington, 1897.
Source Firkin
Colour version of the original pattern inspired by the front cover of 'Old and New Paris', Henry Edwards, 1894.
Source Firkin
Another fairly simple design drawn in Paint.net and vectorized in Inkscape.
Source Firkin
A seamlessly repeating background pattern of wood. The image is procedurally generated, and, I think, it's turned out quite well.
Source V. Hartikainen
Because I love dark patterns, here is Brushed Alum in a dark coating.
Source Tim Ward
This is so subtle you need to bring your magnifier!
Source Carlos Valdez