Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Nicely crafted paper pattern, although a bit on the large side (500x593px).
Source Blaq Annabiosis
Otis Ray Redding was an American soul singer-songwriter, record producer, arranger, and talent scout. So you know.
Source Thomas Myrman
Remixed from a raster on Pixabay that was uploaded by ArtsyBee.
Source Firkin
Like the name suggests, this background image consists of a pattern of dark bricks. It may be an option for you, if you are looking for something that looks like a brick wall for use as a background on web pages. It's not a masterpiece, but looks pretty nice when is tiled.
Source V. Hartikainen
Retro Circles Background 5 No Black
Source GDJ
A subtle shadowed checkered pattern. Increase the lightness for even more subtle sexiness.
Source Josh Green
A large (588x375px) sand-colored pattern for your ever-growing collection. Shrink at will.
Source Alex Tapein
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
Prismatic Geometric Pattern Variation 2 With Background
Source GDJ
More Japanese-inspired patterns, Gold Scales this time.
Source Josh Green
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
Prismatic Isometric Cube Extra Pattern No Background
Source GDJ
An abstract texture of water. It's not perfect, but will do. You may download if you like it.
Source V. Hartikainen
Dark blue concrete wall with some small dust spots.
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
From a drawing in 'A Guide to the Guildhall of the City of London', John Baddeley, 1898.
Source Firkin
A dark pattern made out of 3×3 circles and a 1px shadow. This works well as a carbon texture or background.
Source Atle Mo
A comeback for you: the popular Escheresque, now in black.
Source Patten
Background formed from the original with an emboss effect
Source GDJ
Free tiled background with colorful stripes and white splatter.
Source V. Hartikainen
A background pattern with a look of rough fabric.
Source V. Hartikainen
A seamless pattern created from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin