Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
This one is amazing, truly original. Go use it!
Source Viahorizon
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
Basket Fibers, Basket Texture, Braid Background style CC0 texture.
Source 1A-Photoshop
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
This one takes you back to math class. Classic mathematic board underlay.
Source Josh Green
A seamless pattern of dark bricks. Maybe it's not very realistic, but it looks good in my opinion.
Source V. Hartikainen
The image depicts a seamless pattern which includes hexagonally-aligned gourds with BG in light-brown.
Source Yamachem
Brushed aluminum, in a bright gray version. Lovely 2X as well.
Source Andre Schouten
The perfect pattern for all your blogs about type, or type-related matters.
Source Atle Mo
Prismatic Geometric Pattern Background
Source GDJ
A seamless pattern based on a square tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Prismatic Abstract Geometric Background 3
Source GDJ
A seamless pattern created from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A pattern drawn in Paint.net and vectorized in Inkscape.
Source Firkin
Prismatic Curved Diamond Pattern 8 No Background
Source GDJ
From a drawing in 'Resa i Afrika, genom Angola, Ovampo och Damaraland', P. Moller, 1899.
Source Firkin
This one is amazing, truly original. Go use it!
Source Viahorizon
Clean and crisp lines all over the place. Wrap it up with this one.
Source Dax Kieran
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Tiny circle waves, almost like the ocean.
Source Sagive