A seamless pattern of dark bricks. Maybe it's not very realistic, but it looks good in my opinion.
Source V. Hartikainen
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using 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
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
Free tiled background with colorful stripes and white splatter.
Source V. Hartikainen
Same classic 45-degree pattern, dark version.
Source Luke McDonald
A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.
Source Firkin
Sounds like something from World of Warcraft. Has to be good.
Source Tony Kinard
On a large canvas you can see it tiling, but used on smaller areas, it’s beautiful.
Source Paul Phönixweiß
A black tile-able background with paper-like texture.
Source V. Hartikainen
Zero CC tileable pine bark texture, photographed and made by me. CC0
Source Sojan Janso
A free grid paper background pattern for using on web sites.
Source V. Hartikainen
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Stefan is hard at work, this time with a funky pattern of squares.
Source Stefan Aleksić
Prismatic Abstract Geometric Background 5 No Black
Source GDJ
Seamless Prismatic Geometric Pattern With Background
Source GDJ
Classic vertical lines, in all its subtlety.
Source Cody L
Used correctly, this could be nice. Used in a bad way, all hell will break loose.
Source Atle Mo
Derived from an image that was uploaded to Pixabay by mdmelo.
Source Firkin