I skipped number 3, because it wasn’t all that great. Sorry.
Source Dima Shiper
A repeating background with dark brown stone-like texture and abstract pattern that looks like tree trunks.
Source V. Hartikainen
From a drawing in 'Studies for Stories', Jean Ingelow, 1864.
Source Firkin
Remixed from a JPG that was uploaded to Pixabay by Osckar
Source Firkin
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
A seamless pattern drawn originally in Paint.net by distorting a slice of background pattern 116 and copying the resulting triangle numerous times.
Source Firkin
Derived from a corner decoration itself found as a jpg on Pixabay.
Source Firkin
Number five from the same submitter, makes my job easy.
Source Dima Shiper
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Abstract Geometric Monochrome Pattern Prismatic No Background
Source GDJ
Sometimes you just need the simplest thing.
Source Fabricio
Might not be super subtle, but quite original in its form.
Source Alex Smith
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
Remixed from an image that was uploaded to Pixabay by KirstenStar
Source Firkin
Sharp pixel pattern looking like some sort of fabric.
Source Dmitry
You don’t see many mid-tone patterns here, but this one is nice.
Source Joel Klein
Used the 6th circle pattern designed by Viscious-Speed to create a print that can be used for card making or scrapbooking. Save as a PDF file for the best printing option.
Source Lovinglf
Zero CC tileable pine bark texture, photographed and made by me. CC0
Source Sojan Janso
Dark and hard, just the way we like it. Embossed triangles makes a nice pattern.
Source Ivan Ginev
A nice and simple gray stucco material. Great on its own, or as a base for a new pattern.
Source Bartosz Kaszubowski