This is so subtle I hope you can see it! Tweak at will.
Source Alexandre Naud
Dark, lines, noise, tactile. You get the drift.
Source Anatoli Nicolae
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Detailed but still subtle and quite original. Lovely gray shades.
Source Kim Ruddock
In the spirit of WWDC 2011, here is a dark iOS inspired linen pattern.
Source Atle Mo
A new one called white wall, not by me this time.
Source Yuji Honzawa
Seamless Prismatic Pythagorean Line Art Pattern No Background. A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).
Source GDJ
Nicely executed tiling for an interesting pattern.
Source Ignasi Àvila Padró
Used the 6th circle pattern designed by Viscious-Speed to create a print that can be used for card making or scrapbooking. Save as a PDF file for the best printing option.
Source Lovinglf
This one looks like a cork panel. Feel free to use it as a tiled background on your blog or website.
Source V. Hartikainen
From a drawing in 'Navigations de Alouys de Cademoste.-La Navigation du Capitaine Pierre Sintre', Alvise da ca da Mosto, 1895.
Source Firkin
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin