A huge one at 800x600px. Made from a photo I took going home after work.
Source Atle Mo
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A light brushed aluminum pattern for your pleasure.
Source Tim Ward
A seamless pattern based on a rectangular tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Prismatic Hypnotic Pattern 2 No Background
Source GDJ
Did some testing with Repper Pro tonight, and this gray mid-tone pattern came out.
Source Atle Mo
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Remixed from a drawing in 'The March of Loyalty', Letitia MacClintock, 1884.
Source Firkin
Prismatic Geometric Pattern Background No Black
Source GDJ
Simple combination of stripy squares with their negatively coloured counterparts
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A free pink background pattern.
Source V. Hartikainen