From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Here's an yet another background for websites, with a seamless texture of wood planks this time.
Source V. Hartikainen
Prismatic Geometric Pattern Background 2 No Black
Source GDJ
A large (588x375px) sand-colored pattern for your ever-growing collection. Shrink at will.
Source Alex Tapein
A pattern derived from repeating unit cells each derived from part of a fractal rendering in paint.net.
Source Firkin
I have no idea what J Boo means by this name, but hey – it’s hot.
Source j Boo
A seamless texture of black leather. I think it will look best when used in headers, footers or sidebars.
Source V. Hartikainen
A topographic map like this has actually been requested a few times, so here you go!
Source Sam Feyaerts
Remixed from a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
This was formed by distorting an image of a background on Pixabay.
Source Firkin
He influenced us all. “Don’t be sad because it’s over. Smile because it happened.”
Source Atle Mo
A free background tile with a pattern of pink bump dots. This background tile is sweet! Moreover, it's designed for use as website backgrounds.
Source V. Hartikainen
A seamless chequerboard pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i. Alternative colour scheme.
Source Firkin
Abstract Geometric Monochrome Pattern Prismatic No Background
Source GDJ
CC0 and seamless wellington boot pattern.
Source SliverKnight
A seamless pattern based on a rectangular tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
A criss-cross pattern similar to one I saw mown into a sports field.
Source Firkin
A black tile-able background with paper-like texture.
Source V. Hartikainen
To celebrate the new feature, we need some sparkling diamonds.
Source Atle Mo
Here's a repeatable texture that resembles a light green concrete wall or something similar.
Source V. Hartikainen