From a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
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
You may use it as is, or modify it as you like.
Source V. Hartikainen
Real snow that tiles, not easy. This is not perfect, but an attempt.
Source Atle Mo
Seamless Prismatic Pythagorean Line Art Pattern No Background. A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).
Source GDJ
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
A beautiful dark padded pattern, like an old classic sofa.
Source Chris Baldie
A pattern formed from a squared tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
A light gray fabric pattern with faded vertical stripes.
Source V. Hartikainen
A pattern formed from a photograph of a 16th century ceramic tile.
Source Firkin
White handmade paper pattern with small bumps.
Source Marquis
A free seamless background image with a texture of dark red "canvas". It should look very nice on web sites.
Source V. Hartikainen
You could get a bit dizzy from this one, but it might come in handy.
Source Dertig Media
Free tiled background with colorful stripes and white splatter.
Source V. Hartikainen
This background has abstract texture with some similarities to wood.
Source V. Hartikainen
Submitted in a cream color, but you know how I like it.
Source Devin Holmes
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
Sometimes you just need the simplest thing.
Source Fabricio
Remixed from a drawing in 'Prehistoric Man: researches into the origin of civilisation in the old and the new world', Daniel Wilson, 1876.
Source Firkin