Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
This is indeed a bit strange, but here’s to the crazy ones!
Source Christopher Buecheler
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
Zero CC tileable ground cracked, crackled, texture, made by me.
Source Sojan Janso
A brown seamless wood texture in a form of stripe pattern. The result has turned out pretty well, in my opinion.
Source V. Hartikainen
Zero CC tileable moss or lichen covered stone texture, edited from pixabay. CC0
Source Sojan Janso
From a drawing in 'The Quiver of Love', Walter Crane, 1876
Source Firkin
Abstract Tiled Background Extended 6
Source GDJ
Smooth Polaroid pattern with a light blue tint.
Source Daniel Beaton
A slightly more textured pattern, medium gray. A bit like a potato sack?
Source Bilal Ketab
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
A pale yellow background pattern with vertical stripes. The stripes are partially faded. I think this background image turned out pretty well, especially those faded stripes.
Source V. Hartikainen
The classic 45-degree diagonal line pattern, done right.
Source Jorick van Hees
Remixed from a drawing in 'A Girl in Ten Thousand', Elizabeth Meade, 1896.
Source Firkin
Prismatic Geometric Pattern Background No Black
Source GDJ
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A free repetitive background with a dark concrete wall like texture. This one may be used in dark web site designs.
Source V. Hartikainen
Prismatic Abstract Line Art Pattern Background
Source GDJ
A mid-tone gray pattern with some cement looking texture.
Source Hendrik Lammers