One of the few full-color patterns here, but this one was just too good to pass up.
Source Alexey Usoltsev
Inspired by a pattern found in 'A General History of Hampshire, or the County of Southampton, including the Isle of Wight', Bernard Woodwood, 1861
Source Firkin
Cubes as far as your eyes can see. You know, because they tile.
Source Jan Meeus
An alternative colour scheme to the original seamless pattern.
Source Firkin
Colour version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
ZeroCC tileabel stone granite texture, edited from pixabay. CC0
Source Sojan Janso
This seamless background image should look nice on websites. It has a dark blue gray texture with vertical stripes, it tiles seamlessly and, like all of the background images here, it's free. So, if you like it, take it!
Source V. Hartikainen
A seamless pattern formed from a tile made from page ornament 22. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
People seem to enjoy dark patterns, so here is one with some circles.
Source Atle Mo
A seamlessly tileable pink background texture.
Source V. Hartikainen
This was formed by distorting an image of a background on Pixabay.
Source Firkin
A dark one with geometric shapes and dotted lines.
Source Mohawk Studios
Black brick wall pattern. Brick your site up!
Source Alex Parker
A free pink background pattern.
Source V. Hartikainen
Remixed from a drawing in 'Paul's Sister', Frances Peard, 1889.
Source Firkin
A seamless pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i. Derived from a design in 'Storia del Palazzo Vecchio in Firenze', Aurelio Gotti, 1889.
Source Firkin
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Prismatic Abstract Line Art Pattern Background
Source GDJ
Brushed aluminum, in a bright gray version. Lovely 2X as well.
Source Andre Schouten
Never out of fashion and so much hotter than the 45º everyone knows, here is a sweet 60º line pattern.
Source Atle Mo
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Remixed from a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
Formed from a tile based on a drawing from 'Viaggi d'un artista nell'America Meridionale', Guido Boggiani, 1895.
Source Firkin