A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Medium gray fabric pattern with 45-degree lines going across.
Source Atle Mo
Prismatic Groovy Concentric Background 4 No Black
Source GDJ
Because I love dark patterns, here is Brushed Alum in a dark coating.
Source Tim Ward
An alternative colour scheme for the original background.
Source Firkin
Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Prismatic Snowflakes Pattern 2 No Background
Source GDJ
Sharp but soft triangles in light shades of gray.
Source Pixeden
Super detailed 16×16 tile that forms a beautiful pattern of straws.
Source Pavel
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
From a drawing in 'Storia del Palazzo Vecchio in Firenze', Aurelio Gotti, 1889.
Source Firkin
A brown seamless wood texture in a form of stripe pattern. The result has turned out pretty well, in my opinion.
Source V. Hartikainen
Continuing the geometric trend, here is one more.
Source Mike Warner
It almost looks a bit blurry, but then again, so are fishes.
Source Petr Šulc
Snap! It’s a pattern, and it’s not grayscale! Of course you can always change the color in Photoshop.
Source Atle Mo
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
Almost like little fish shells, or dragon skin.
Source Graphiste
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Very dark pattern with some noise and 45-degree lines.
Source Stefan Aleksić
You could get a bit dizzy from this one, but it might come in handy.
Source Dertig Media
A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso