Dare I call this a «flat pattern»? Probably not.
Source Dax Kieran
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-i
Source Firkin
A light gray wall or floor (you decide) of concrete.
Source Atle Mo
Embossed lines and squares with subtle highlights.
Source Alex Parker
A seamless background texture of old cardboard.
Source V. Hartikainen
Just what the name says, paper fibers. Always good to have.
Source Heliodor jalba
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
Zero CC asphalt, pavement, texture, photographed and made by me. CC0 WARNING I FOUND A SEAM ON THIS TEXTURE
Source Sojan Janso
8 by 8 pixels, and just what the title says.
Source pixilated
Tile available in Inkscape using shift-alt-i on the selected rectangle
Source Firkin
From a drawing in 'Hundert Jahre in Wort und Bild', S. Stefan, 1899.
Source Firkin
To celebrate the new feature, we need some sparkling diamonds.
Source Atle Mo
Prismatic Groovy Concentric Background 4
Source GDJ
A beautiful dark padded pattern, like an old classic sofa.
Source Chris Baldie
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
You know you love wood patterns, so here’s one more.
Source Richard Tabor
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
One more brick pattern. A bit more depth to this one.
Source Benjamin Ward
Pattern Background, Texture, Photoshop Structure style CC0 texture.
Source Darkmoon1968
Here's a new background image for websites with a seamless pink texture. It should look beautiful with website themes where light pink background is needed. The background is seamless, therefore it should be used as a tiled background.
Source V. Hartikainen
You just can’t get enough of the fabric patterns, so here is one more for your collection.
Source Krisp Designs
Abstract Geometric Monochrome Pattern Prismatic No Background
Source GDJ
A background pattern inspired by designs seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
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
The act or state of corrugating or of being corrugated, a wrinkle; fold; furrow; ridge.
Source Anna Litvinuk