From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
A simple example on using clones. You can generate a nice base for a pattern fill quickly with it.
Source Lazur URH
This is sort of fresh, but still feels a bit old school.
Source Martuchox
A free green background pattern with a pattern of rhombuses on a seamless texture. Feel free to use it as a tiled background image on your web site.
Source V. Hartikainen
From a drawing in 'Kingsdene', Maria Fetherstonehaugh, 1878.
Source Firkin
The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Prismatic Curved Diamond Pattern 4 No Background
Source GDJ
Colorful Floral Background 3 No Black
Source GDJ
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
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
The edges of all the red objects line up either vertically or horizontally, but it doesn't appear so. Made from a square tile that can be got by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Don’t look at this one too long if you’re high on something.
Source Luuk van Baars
A dark striped seamless pattern suitable for use as a background on websites.
Source V. Hartikainen
You know, tiny and sharp. I’m sure you’ll find a use for it.
Source Atle Mo
This background pattern contains worn out colorful stripes as a texture.
Source V. Hartikainen
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A slightly more textured pattern, medium gray. A bit like a potato sack?
Source Bilal Ketab
The image depicts the Japanese Edo pattern called "seigaiha" or "青海波" meaning "blue -sea- wave".I hope it's suitable for the summer season.
Source Yamachem
More in the paper realm, this time with fibers.
Source Jorge Fuentes
A background formed from an image of an old tile on the New York Metropolitan Museum of Art website. To get the base tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
First pattern tailor-made for Retina, with many more to come. All the old ones are upscaled, in case you want to re-download.
Source Atle Mo
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
From a design found in 'History of the Virginia Company of London; with letters to and from the first Colony, never before printed', Edward Neill, 1869.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use 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
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight