I skipped number 3, because it wasn’t all that great. Sorry.
Source Dima Shiper
Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
Just like your old suit, all striped and smooth.
Source Alex Berkowitz
More in the paper realm, this time with fibers.
Source Jorge Fuentes
Prismatic Abstract Line Art Pattern Background
Source GDJ
A classic dark tile for a bit of vintage darkness.
Source Listvetra
This ons is quite old school looking. Retro, even. I like it.
Source Arno Declercq
Background Wall, Art Abstract, Block Well & CC0 texture.
Source Ractapopulous
Derived from an image that was uploaded to Pixabay by Darkmoon1968
Source Firkin
A pattern drawn in Paint.net and vectorized in Vector Magic.
Source Firkin
You know, tiny and sharp. I’m sure you’ll find a use for it.
Source Atle Mo
A seamless web texture of "green stone".
Source V. Hartikainen
Paper pattern with small dust particles and 45-degree strokes.
Source Atle Mo
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 pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
From a drawing in 'Kingsdene', Maria Fetherstonehaugh, 1878.
Source Firkin
Could remind you a bit of those squares in Super Mario Bros, yeh?
Source Jeff Wall
A pattern formed from a squared tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Coming in at 666x666px, this is an evil big pattern, but nice and soft at the same time.
Source Atle Mo
Remixed from a drawing in 'Paul's Sister', Frances Peard, 1889.
Source Firkin
The first pattern on here using opacity. Try it on a site with a colored background, or even using mixed colors.
Source Nathan Spady
Tiny circle waves, almost like the ocean.
Source Sagive
Seamless pattern the basic tile for which can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A seamless pattern from a tile made from a jpg on Pixabay. To get the tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
To get the repeating unit, select the rectangle in Inkscape and use shift+alt+i
Source Firkin
Dark Tile-able Grunge Texture. I think this texture can be classified as grunge. It's free and seamless, as always.
Source V. Hartikainen
Prismatic Geometric Pattern Background No Black
Source GDJ