A seamless pattern of dark bricks. Maybe it's not very realistic, but it looks good in my opinion.
Source V. Hartikainen
Black brick wall pattern. Brick your site up!
Source Alex Parker
This one is rather fun and playful. The 2X could be used at 1X too!
Source Welsley
This background pattern contains worn out colorful stripes as a texture.
Source V. Hartikainen
Spice up your next school project with this icon background.
Source Swetha
Scanned some rice paper and tiled it up for you. Enjoy.
Source Atle Mo
From a drawing in 'Gately's World's Progress', Charles Beale, 1886.
Source Firkin
Background Wall, Art Abstract, Blue Well & CC0 texture.
Source Ractapopulous
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Abstract Tiled Background Extended 10
Source GDJ
Super dark, crisp and detailed. And a Kill Bill reference.
Source Badhon Ebrahim
Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
A chequerboard pattern with a fruit theme. The fruits are from a posting by inkscapeforum.it.
Source Firkin
It’s like Shine Dotted’s sister, only rotated 45 degrees.
Source mediumidee
A free seamless background pattern for use on websites.
Source V. Hartikainen
From a drawing in 'A Guide to the Guildhall of the City of London', John Baddeley, 1898.
Source Firkin
Inspired by a pattern seen on a public domain image of a very old tile. To get the unit cell, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Inspired by a JPG that was uploaded to Pixabay by kokon_art
Source Firkin
ZeroCC tileable stone texture, edited from pixabay, CC0
Source Sojan Janso
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin