To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Prepared mostly as a raster in Paint.net and vectorised.
Source Firkin
Paper pattern with small dust particles and 45-degree strokes.
Source Atle Mo
Derived from an image that was uploaded to Pixabay by mdmelo.
Source Firkin
A free black metallic background pattern. Here's a new pattern I made that looks metallic.
Source V. Hartikainen
A seamless green background texture. The image is distributed under a Creative Commons License (like all of the images here).
Source V. Hartikainen
Prismatic Polka Dots Mark II 2 No Background
Source GDJ
A seamless pattern formed from background pattern 102
Source Firkin
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin