An abstract Background pattern of purple twisty patterns.
Source TikiGiki
Prismatic Abstract Geometric Background 5 No Black
Source GDJ
Not strictly seamless in that opposite edges are not identical. But they do marry up to make an interesting pattern
Source Firkin
Vector version of a JPG that was uploaded to Pixabay by theasad121
Source Firkin
CC0 and seamless wellington boot pattern.
Source SliverKnight
Classic 45-degree pattern, light version.
Source Luke McDonald
Remixed from a raster on Pixabay, that was uploaded by ArtsyBee.
Source Firkin
An alternative colour scheme for the original background.
Source Firkin
Derived from an image that was uploaded to Pixabay by Kaz
Source Firkin
A seamless web texture of "green stone".
Source V. Hartikainen
Simple gray checkered lines, in light tones.
Source Radosław Rzepecki
Pattern produced in Paint.net using the Vibrato plug-in.
Source Firkin
The file was named striped lens, but hey – Translucent Fibres works too.
Source Angelica
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A free seamless background pattern for use on websites.
Source V. Hartikainen
Not the most creative name, but it’s a good all-purpose light background.
Source Dmitry
A slightly grainy paper pattern with small horizontal and vertical strokes.
Source Atle Mo
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Kaleidoscope Prismatic Abstract No Background
Source GDJ