A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).
Source GDJ
A new take on the black linen pattern. Softer this time.
Source Atle Mo
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Prismatic Triangular Background Design Mark II 5
Source GDJ
Sweet and subtle white plaster with hints of noise and grunge.
Source Phil Maurer
Prismatic Polka Dots Mark II 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 seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
Seamless Dark Grunge Texture. Here's a new grunge texture for use as a background.
Source V. Hartikainen
Formed by distorting the inside front cover of 'Diversæ insectarum volatilium : icones ad vivum accuratissmè depictæ per celeberrimum pictorem', Jacob Hoefnagel, 1630.
Source Firkin
Small dots with minor circles spread across to form a nice mosaic.
Source John Burks
This yellow background consists of a pattern of glossy gold buttons arranged in polka dot style on a seamless texture. Here's a pale yellow background pattern. Feel free to use it for your needs!
Source V. Hartikainen
A playful triangle pattern with different shades of gray.
Source Dimitrie Hoekstra
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I.
Source Firkin
A free tileable background colored in off-white (antique white) color.
Source V. Hartikainen