From an image on opengameart.org shared by rubberduck.
Source Firkin
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
Did some testing with Repper Pro tonight, and this gray mid-tone pattern came out.
Source Atle Mo
Remixed from a drawing that was uploaded to Pixabay by ractapopulous
Source Firkin
A seamless chequerboard pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i. Alternative colour scheme.
Source Firkin
Fix and cc0 to get the tile this is based on.
Source SliverKnight
The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
It has waves, so make sure you don’t get sea sickness.
Source CoolPatterns
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Three shades of gray makes this pattern look like a small carbon fiber surface. Great readability even for small fonts.
Source Atle Mo
On a large canvas you can see it tiling, but used on smaller areas, it’s beautiful.
Source Paul Phönixweiß
Prismatic Groovy Concentric Background 3 No Black
Source GDJ
ZeroCC tileable wood boards texture, photographed and made by me. CC0
Source Sojan Janso
Prismatic Groovy Concentric Background 2
Source GDJ
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I.
Source Firkin
Actually, there's no clouds in it, but I think it looks quite nice.
Source V. Hartikainen
Drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
I asked Gjermund if he could make a pattern for us – result!
Source Gjermund Gustavsen
Prismatic Geometric Tessellation Pattern 3 No Background
Source GDJ
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
A free web background image with a seamless concrete-like texture and an Indian-red color.
Source V. Hartikainen