Here's a subtle marble-like background for use on websites.
Source V. Hartikainen
The act or state of corrugating or of being corrugated, a wrinkle; fold; furrow; ridge.
Source Anna Litvinuk
This one is rather fun and playful. The 2X could be used at 1X too!
Source Welsley
A dark one with geometric shapes and dotted lines.
Source Mohawk Studios
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Black paper texture, based on two different images.
Source Atle Mo
Based from Design Kindle
From drawing in 'Musings in Maoriland', Thomas Bracken, 1890.
Source Firkin
This one needs to be used in small areas; you can see it repeat.
Source Luca
Love me some light mesh on a Monday. Sharp.
Source Wilmotte Bastien
Got some felt in my mailbox today, so I scanned it for you to use.
Source Atle Mo
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Bright gray tones with a hint of some metal surface.
Source Hendrik Lammers
A seamless pattern created from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
The tile this is formed from can be retrieved in Inkscape by selecting the rectangle and using shift+alt+i
Source Firkin
This one could be the shirt of a golf player. Angled lines in different thicknesses.
Source Olivier Pineda
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Derived from a drawing in 'Elfrica. An historical romance of the twelfth century', Charlotte Boger, 1885
Source Firkin
Seamless Dark Grunge Texture. Here's a new grunge texture for use as a background.
Source V. Hartikainen
This was formed by distorting an image of a background on Pixabay.
Source Firkin
Drawn in Paint.net using the kaleidoscope plug-in and vectorised.
Source Firkin
A seamless dark leather-like background texture with diagonal lines that look like stitches.
Source V. Hartikainen
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Prismatic Groovy Concentric Background 5 No Black
Source GDJ