Sort of like the Photoshop transparent background, but better!
Source Alex Parker
Medium gray fabric pattern with 45-degree lines going across.
Source Atle Mo
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
A seamless tessellation pattern. To get the tile this is formed from, select the pattern in Inkscape and use shift+alt+i.
Source Firkin
A simple example on using clones. You can generate a nice base for a pattern fill quickly with it.
Source Lazur URH
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
This is the third pattern called Dark Denim, but hey, we all love them!
Source Brandon Jacoby
Prismatic Groovy Concentric Background 4 No Black
Source GDJ
From a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
Don’t look at this one too long if you’re high on something.
Source Luuk van Baars
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
A simple but elegant classic. Every collection needs one of these.
Source Christopher Burton
Prismatic Geometric Tessellation Pattern 4 No Background
Source GDJ
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin