You don’t see many mid-tone patterns here, but this one is nice.
Source Joel Klein
This one could be the shirt of a golf player. Angled lines in different thicknesses.
Source Olivier Pineda
From a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
Small gradient crosses inside 45-degree boxes, or bigger crosses if you will.
Source Wassim
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A repeating gloomy background image. This one consists of a pattern of black chains layered on top of a dark textured background.
Source V. Hartikainen
From an image on opengameart.org shared by rubberduck.
Source Firkin
Classic vertical lines, in all its subtlety.
Source Cody L
8 by 8 pixels, and just what the title says.
Source pixilated
Prismatic Rounded Squares Grid 4 No Background
Source GDJ
You just can’t get enough of the fabric patterns, so here is one more for your collection.
Source Krisp Designs
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
It looks like a polished stone surface to me. Download it for free, as always.
Source V. Hartikainen
Inspired by an image that was uploaded to Pixabay by geralt
Source Firkin
You know I love paper patterns. Here is one from Stephen. Say thank you!
Source Stephen Gilbert
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I. A version of the original with random colors.
Source Firkin
A colourful background drawn originally in paint.net and vectorised in Vector Magic.
Source Firkin
A free seamless background image with abstract texture of green "curtain".
Source V. Hartikainen
Background Wall, Art Abstract, Blue Well & CC0 texture.
Source Ractapopulous
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
In the spirit of WWDC 2011, here is a dark iOS inspired linen pattern.
Source Atle Mo
Love the style on this one, very fresh. Diagonal diamond pattern. Get it?
Source INS
From a drawing in 'Handbook of the excursions proposed to be made by the Lincoln Diocesan Architectural Society, on the 27th and 28th of May, 1857', Edward Trollope, 1857.
Source Firkin