I guess this is inspired by the city of Ravenna in Italy and its stone walls.
Source Sentel
Prismatic Abstract Background Design No Black
Source GDJ
Some rectangles, a bit of dust and grunge, plus a hint of concrete.
Source Atle Mo
Prismatic Polka Dots Mark II No Background
Source GDJ
Prismatic Abstract Geometric Background 3
Source GDJ
A pattern formed from a squared tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
The image depicts an edo-era pattern called "same-komon" or "鮫小紋"which looks like a shark skin.The "same" in Japanese means shark in English.
Source Yamachem
This pattern comes in orange, and it looks as if it is "made of glass".
Source V. Hartikainen
Prismatic Hypnotic Pattern 2 No Background
Source GDJ
From a drawing in 'Resa i Afrika, genom Angola, Ovampo och Damaraland', P. Moller, 1899.
Source Firkin
Feel free to use this seamless background texture as a background on a web site. It's colored in a light pink color and is seamlessly tile-able.
Source V. Hartikainen
I have no idea what J Boo means by this name, but hey – it’s hot.
Source j Boo
The classic 45-degree diagonal line pattern, done right.
Source Jorick van Hees
A seamless pattern formed from a sports car on clker.com. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Prismatic Abstract Geometric Background 4 No Black
Source GDJ
A comeback for you: the popular Escheresque, now in black.
Source Patten
Turn your site into a dragon with this great scale pattern.
Source Alex Parker
Original minus the background
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
An abstract pale yellow paper-like background with stains colored in yellow and green.
Source V. Hartikainen