A simple but elegant classic. Every collection needs one of these.
Source Christopher Burton
ZeroCC tileable stone texture, edited from pixabay. CC0
Source Sojan Janso
Because I love dark patterns, here is Brushed Alum in a dark coating.
Source Tim Ward
Based on several public domain drawings on Wikimedia Commons. This was formed from a rectangular tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i
Source Firkin
It almost looks a bit blurry, but then again, so are fishes.
Source Petr Šulc
Inspired by a drawing seen in 'City of Liverpool', James Picton, 1883.
Source Firkin
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
Alternative colour scheme to the original.
Source Firkin
A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.
Source Firkin
Actually, there's no clouds in it, but I think it looks quite nice.
Source V. Hartikainen
A seamless pattern formed from a square tile based on a jpg on Pixabay. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I.
Source Firkin
Prismatic Abstract Geometric Background 4 No Black
Source GDJ
Green Web Background, Seamless tile.
Source V. Hartikainen
Here's a new paper-like background for free use on personal and commercial projects (this applies to all background patterns here).
Source V. Hartikainen
A classic dark tile for a bit of vintage darkness.
Source Listvetra
Prismatic Curved Diamond Pattern 3 No Background
Source GDJ
After 1 comes 2, same but different. You get the idea.
Source Hendrik Lammers
Remixed from a vector adapted from a jpg on Pixabay. The tile this is constructed from can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Beautiful dark noise pattern with some dust and grunge.
Source Vincent Klaiber