I guess this is inspired by the city of Ravenna in Italy and its stone walls.
Source Sentel
Did anyone say The Hoff? This pattern is in no way related to Baywatch.
Source Josh Green
A seamless pattern based on a tile that can be achieved by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
This pattern comes in orange, and it looks as if it is "made of glass".
Source V. Hartikainen
Not even 1kb, but very stylish. Gray thin lines.
Source Struck Axiom
Fix and cc0 to get the tile this is based on.
Source SliverKnight
Prismatic Curved Diamond Pattern 2 No Background
Source GDJ
I have no idea what J Boo means by this name, but hey – it’s hot.
Source j Boo
Heavy depth and shadows here, but might work well on some mobile apps.
Source Damian Rivas
From a drawing in 'Storia del Palazzo Vecchio in Firenze', Aurelio Gotti, 1889.
Source Firkin
A background pattern with a look of rough fabric.
Source V. Hartikainen
The image depicts a seamless pattern of Japanese Edo pattern called "kikkou-matsu" or "亀甲松" meaning " tortoiseshell-pinetree".The real pinetree is like this: https://jp.pinterest.com/pin/500744052301065077/
Source Yamachem
From a drawing in 'Friend or Fortune? The story of a strange year', Robert Overton, 1897.
Source Firkin
Derived from an image that was uploaded to Pixabay by Darkmoon1968
Source Firkin
Derived from an image that was uploaded to Pixabay by Kaz
Source Firkin
A free seamless background image with a texture of dark red "canvas". It should look very nice on web sites.
Source V. Hartikainen
Prismatic Abstract Line Art Pattern Background
Source GDJ
Dark, crisp and subtle. Tiny black lines on top of some noise.
Source Wilmotte Bastien
Everyone needs some stardust. Sprinkle it on your next project.
Source Atle Mo
Super subtle indeed, a medium gray pattern with tiny dots in a grid.
Source Designova