Drawn in Paint.net using the kaleidoscope plug-in and vectorised.
Source Firkin
A dark pattern made out of 3×3 circles and a 1px shadow. This works well as a carbon texture or background.
Source Atle Mo
Prismatic Groovy Concentric Background 2 No Black
Source GDJ
Might not be super subtle, but quite original in its form.
Source Alex Smith
One of the few full-color patterns here, but this one was just too good to pass up.
Source Alexey Usoltsev
A green background pattern with warped vertical stripes and a grunge look.
Source V. Hartikainen
A repeating gloomy background image. This one consists of a pattern of black chains layered on top of a dark textured background.
Source V. Hartikainen
Prismatic Abstract Geometric Background derived from an image on Pixabay.
Source GDJ
From a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
Sharp diamond pattern. A small 24x18px tile.
Source Tom Neal
Coming in at 666x666px, this is an evil big pattern, but nice and soft at the same time.
Source Atle Mo
A very dark asfalt pattern based off of a photo taken with my iPhone.
Source Atle Mo
Alternative colour scheme to the original.
Source Firkin
Heavy depth and shadows here, but might work well on some mobile apps.
Source Damian Rivas
A pattern derived from repeating unit cells each derived from part of a fractal rendering in paint.net.
Source Firkin
This was formed by distorting an image of a background on Pixabay.
Source Firkin
Beautiful dark noise pattern with some dust and grunge.
Source Vincent Klaiber
A yellow tiled background... Blurriness, bokeh effect and rectangles pattern in one mix.
Source V. Hartikainen
A pattern drawn in Paint.net and vectorized in Inkscape.
Source Firkin