A seamless tessellation pattern. To get the tile this is formed from, select the pattern in Inkscape and use shift+alt+i.
Source Firkin
Submitted by DomainsInfo – wtf, right? But hey, a free pattern.
Source DomainsInfo
Remixed from a PNG that was uploaded to Pixabay by k_jprather
Source Firkin
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
A seamless pattern the starting point for which was a 'rainbow twist' texture in Paint.net.
Source Firkin
The tile this is based on was adapted from an image that was uploaded to Pixabay by frolicsomepl. It can be had in Inkscape by selecting the rectangle and using shift+alt+i
Source Firkin
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
Seamless Green Tile Background
Source V. Hartikainen
Derived from a corner decoration itself found as a jpg on Pixabay.
Source Firkin
Here's a repeatable texture that resembles a light green concrete wall or something similar.
Source V. Hartikainen
A simple circle. That’s all it takes. This one is even transparent, for those who like that.
Source Saqib
Turn your site into a dragon with this great scale pattern.
Source Alex Parker
Prismatic Curved Diamond Pattern 8 No Background
Source GDJ
Pattern produced in Paint.net using the Vibrato plug-in.
Source Firkin
Background pattern made in "Grunge-Like" style. Available in both SVG and JPG formats. Edit to your needs then click the download button.
Source V. Hartikainen
The classic 45-degree diagonal line pattern, done right.
Source Jorick van Hees
This was formed by distorting an image of a background on Pixabay.
Source Firkin
A seamless texture of worn out "cardboard".
Source V. Hartikainen
I guess this is inspired by the city of Ravenna in Italy and its stone walls.
Source Sentel