A background formed from an image of an old tile on the New York Metropolitan Museum of Art website. To get the base tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Retro Circles Background 8 No Black
Source GDJ
Derived from an image that was uploaded to Pixabay by Kaz
Source Firkin
Did anyone say The Hoff? This pattern is in no way related to Baywatch.
Source Josh Green
This one is amazing, truly original. Go use it!
Source Viahorizon
Zero CC tileable pine bark texture, photographed and made by me. CC0
Source Sojan Janso
This background has abstract texture with some similarities to wood.
Source V. Hartikainen
Prismatic Groovy Concentric Background 3 No Black
Source GDJ
Just what the name says, paper fibers. Always good to have.
Source Heliodor jalba
The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Prismatic Abstract Geometric Background 5 No Black
Source GDJ
Might not be super subtle, but quite original in its form.
Source Alex Smith
A pale olive green background with a seamless texture.
Source V. Hartikainen
A cute x, if you need that sort of thing.
Source Juan Scrocchi
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Super detailed 16×16 tile that forms a beautiful pattern of straws.
Source Pavel
One of the few full-color patterns here, but this one was just too good to pass up.
Source Alexey Usoltsev
The tile this is formed from can be retrieved in Inkscape by selecting the rectangle and using shift+alt+i
Source Firkin
Oh yes, it happened! A pattern in full color.
Source Atle Mo
A large (588x375px) sand-colored pattern for your ever-growing collection. Shrink at will.
Source Alex Tapein
Zero CC tileable cork floor, photographed and made by me. CC0
Source Sojan Janso
This could be a hippy vintage wallpaper.
Source Tileable Patterns
The tile for this is based on a repeating unit close to a design on Pixabay. It can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin