Pattern Background, Texture, Photoshop Structure style CC0 texture.
Source Darkmoon1968
Simple combination of stripy squares with their negatively coloured counterparts
Source Firkin
Thin lines, noise and texture creates this crisp dark denim pattern.
Source Marco Slooten
The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
A seamless pattern created from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
From an image on opengameart.org shared by rubberduck.
Source Firkin
Sharp but soft triangles in light shades of gray.
Source Pixeden
Otis Ray Redding was an American soul singer-songwriter, record producer, arranger, and talent scout. So you know.
Source Thomas Myrman
Inspired by this, I came up with this pattern. Madness!
Source Atle Mo
This is the remix of an OCAL clipart called "Rain on Window" uploaded by "pagarmidna".Thanks.This is a seamless pattern of raindrops.
Source Yamachem
Prismatic Polyskelion Pattern No Background
Source GDJ
From a drawing of the coat of arms of the Ottoman Empire on Wikimedia.
Source Firkin
A white version of the very popular linen pattern.
Source Ant Ekşiler
Prismatic Curved Diamond Pattern 3 No Background
Source GDJ
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
This one is amazing, truly original. Go use it!
Source Viahorizon
Tiny little fibers making a soft and sweet look.
Source Badhon Ebrahim
Prismatic Abstract Geometric Background 5 No Black
Source GDJ
Different from the original in being a simple tile stored as a pattern definition, rather than numerous repeated objects. Hence easy and quick to give this pattern to objects of different shapes. To get the tile in Inkscape, select the rectangle and use shift+alt+i.
Source Firkin