This background pattern has futuristic look. So, maybe it could be used on websites or blogs dedicated to video games?!
Source V. Hartikainen
Abstract Tiled Background Extended 12
Source GDJ
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
This is so subtle I hope you can see it! Tweak at will.
Source Alexandre Naud
A seamless pattern formed from background pattern 102
Source Firkin
This background pattern contains worn out colorful stripes as a texture.
Source V. Hartikainen
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 pattern created from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
This one looks like a cork panel. Feel free to use it as a tiled background on your blog or website.
Source V. Hartikainen
The image depicts a seamless pattern of a Japanese family crest called "chidori" in Japanese .A chidori in Japanese means a plover in English.
Source Yamachem
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Thin lines, noise and texture creates this crisp dark denim pattern.
Source Marco Slooten
From a drawing in 'Hubert Montreuil, or the Huguenot and the Dragoon', Francisca Ouvry, 1873.
Source Firkin
This light yellow background pattern consists of an irregular pattern of spots. Here's a light background pattern with yellowish tint.
Source V. Hartikainen
And some more testing, this time with Seamless Studio. It’s Robots FFS!
Source Seamless Studio
Background Wall, Art Abstract, Block Well & CC0 texture.
Source Ractapopulous
Remixed from a drawing in 'The Canadian horticulturist', 1892
Source Firkin
The basic shapes never get old. Simple triangle pattern.
Source Atle Mo
Prismatic Curved Diamond Pattern 8 No Background
Source GDJ
One can never have too few rice paper patterns, so here is one more.
Source Atle Mo