There are many carbon patterns, but this one is tiny.
Source Designova
Classic 45-degree pattern, light version.
Source Luke McDonald
Hey, you never know when you’ll need a bird pattern, right?
Source Pete Fecteau
Not the most creative name, but it’s a good all-purpose light background.
Source Dmitry
Derived from a drawing in 'The Murmur of the Shells', Samuel Cowen, 1879.
Source Firkin
Floral patterns will never go out of style, so enjoy this one.
Source Lasma
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
From a design found in 'History of the Virginia Company of London; with letters to and from the first Colony, never before printed', Edward Neill, 1869.
Source Firkin
The edges of all the red objects line up either vertically or horizontally, but it doesn't appear so. Made from a square tile that can be got by selecting the rectangle in Inkscape 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
A black tile-able background with paper-like texture.
Source V. Hartikainen
A seamless pattern formed from cross 4. To get the original tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A free seamless background image with abstract texture of green "curtain".
Source V. Hartikainen
A pattern formed from a photograph of a 16th century ceramic tile.
Source Firkin
Not the most creative name, but it’s a good all-purpose light background.
Source Dmitry
A seamless pattern drawn originally in Paint.net by distorting a slice of background pattern 116 and copying the resulting triangle numerous times.
Source Firkin
Simple combination of stripy squares with their negatively coloured counterparts
Source Firkin
A seamless pattern the starting point for which was a 'light rays' rendering in Paint.net.
Source Firkin
Abstract Tiled Background Extended 8
Source GDJ
Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Did anyone say The Hoff? This pattern is in no way related to Baywatch.
Source Josh Green
An abstract texture of black metal pipes (seamless).
Source V. Hartikainen