Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
Prismatic Hexagonalist Pattern No Background
Source GDJ
Coming in at 666x666px, this is an evil big pattern, but nice and soft at the same time.
Source Atle Mo
A dark pattern made out of 3×3 circles and a 1px shadow. This works well as a carbon texture or background.
Source Atle Mo
A bit of scratched up grayness. Always good.
Source Dmitry
Tile available in Inkscape using shift-alt-i on the selected rectangle
Source Firkin
Horizontal and vertical lines on a light gray background.
Source Adam Anlauf
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Neat little photography icon pattern.
Source Hossam Elbialy
Floral patterns will never go out of style, so enjoy this one.
Source Lasma
Inspired by a 1930s wallpaper pattern I saw on TV.
Source Firkin
A simple circle. That’s all it takes. This one is even transparent, for those who like that.
Source Saqib
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
A free background tile with a pattern of pink bump dots. This background tile is sweet! Moreover, it's designed for use as website backgrounds.
Source V. Hartikainen
One more in the line of patterns inspired by Japanese/Asian styles. Smooth.
Source Kim Ruddock
This one is amazing, truly original. Go use it!
Source Viahorizon
From a drawing in 'La Principauté de Liège et les Pays-Bas au XVIe siècle', Société des Bibliophiles Liégeois ,1887.
Source Firkin
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
A topographic map like this has actually been requested a few times, so here you go!
Source Sam Feyaerts
A background pattern with green vertical stripes. A new striped background pattern. This time a green one.
Source V. Hartikainen
Bumps, highlight and shadows – all good things.
Source Badhon Ebrahim
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
The basic shapes never get old. Simple triangle pattern.
Source Atle Mo