Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
Remixed from a drawing that was uploaded to Pixabay by ractapopulous
Source Firkin
Prismatic Groovy Concentric Background 3 No Black
Source GDJ
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
Remixed from an image that was uploaded to Pixabay by Pixeline
Source Firkin
Inspired by a drawing in 'Kulturgeschichte', Freidrich Hellwald, 1896.
Source Firkin
Derived from an image that was uploaded to Pixabay by Kaz
Source Firkin
Greyscale version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
Prismatic Curved Diamond Pattern 2 No Background
Source GDJ
A seamless pattern the unit cell for which can be had 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
I love cream! 50x50px and lovely in all the good ways.
Source Thomas Myrman
Lovely pattern with splattered vintage speckles.
Source David Pomfret
This is so subtle you need to bring your magnifier!
Source Carlos Valdez
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
Continuing the geometric trend, here is one more.
Source Mike Warner
A free background pattern with abstract green tiles.
Source V. Hartikainen
Light square grid pattern, great for a “DIY projects” sort of website, maybe?
Source Rafael Almeida
Kaleidoscope Prismatic Abstract No Background
Source GDJ
Remixed from an image that was uploaded to Pixabay by Pixeline
Source Firkin
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin