High detail stone wall with minor cracks and specks.
Source Projecteightyfive
A free seamless background image with abstract texture of green "curtain".
Source V. Hartikainen
Floral patterns will never go out of style, so enjoy this one.
Source Lasma
Wild Oliva or Oliva Wilde? Darker than the others, sort of a medium dark pattern.
Source Badhon Ebrahim
Pattern formed from simple shapes. Black version.
Source Firkin
Derived from a drawing in 'The Murmur of the Shells', Samuel Cowen, 1879.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
An emulated “transparent” background pattern, like that of all kinds of computer graphics software.
Source AdamStanislav
A background pattern with a look of rough fabric.
Source V. Hartikainen
It was called Navy Blue, but I made it dark. You know, the way I like it.
Source Ethan Hamilton
Prismatic Isometric Cube Extra Pattern No Background
Source GDJ
Abstract Arbitrary Geometric Background derived from an image on Pixabay.
Source GDJ
A gray background pattern with a texture of textile. Suits perfectly for web design.
Source V. Hartikainen
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
Derived from an image that was uploaded to Pixabay by Darkmoon1968
Source Firkin
A very dark spotted twinkle pattern for your twinkle needs.
Source Badhon Ebrahim
One more from Badhon, sharp horizontal lines making an embossed paper feeling.
Source Badhon Ebrahim
Your eyes can trip a bit from looking at this – use it wisely.
Source Michal Chovanec
A seamless pattern formed from background pattern 102
Source Firkin
Not a pattern for fabrics, but one produced from a jpg of a stack of fabric items that was posted on Pixabay. The tile that this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin