A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
From a drawing of the coat of arms of the Ottoman Empire on Wikimedia.
Source Firkin
Light gray paper pattern with small traces of fiber and some dust.
Source Atle Mo
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
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
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A new take on the black linen pattern. Softer this time.
Source Atle Mo
Imagine you zoomed in 1000X on some fabric. But then it turned out to be a skeleton!
Source Angelica
A pale olive green background with a seamless texture.
Source V. Hartikainen
The following orange background pattern resembles a honeycomb.
Source V. Hartikainen
Dark, square, clean and tidy. What more can you ask for?
Source Jaromír Kavan
Gold Triangular Seamless Pattern No Background
Source GDJ
A free pink background pattern.
Source V. Hartikainen
This background texture resembles stone. It may be used as a background on web pages or on some of their html elements (header, borders, menu bar, etc.). Just modify it for your needs.
Source V. Hartikainen
A free black metallic background pattern. Here's a new pattern I made that looks metallic.
Source V. Hartikainen
Prismatic Groovy Concentric Background No Black
Source GDJ
A beautiful dark wood pattern, superbly tiled.
Source Omar Alvarado
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin