Retro Circles Background 8@2X #436
 Dark  CC 0

Retro Circles Background 8

Source GDJ

 More Textures
Prismatic Curved Diamond Pattern 3 No Background #162
 Diamond  CC 0

Prismatic Curved Diamond Pattern 3 No Background

Source GDJ

Light Aluminum #304
 Wall  CC BY-SA 3.0

Used correctly, this could be nice. Used in a bad way, all hell will break loose.

Source Atle Mo

Decorative divider 274 #1922
 Dark  CC 0

Redrawn based on a drawing in 'По Сѣверо-Западу Россіи' Konstantin Sluchevsky, 1897.

Source Firkin

Background pattern 266 #2068
 Dark  CC 0

Remixed from a drawing in 'Some account of the Worshipful Company of Ironmongers', John Nicholl, 1866.

Source Firkin

Background pattern 213 #2412
 Dark  CC 0

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

Prismatic Geometric Pattern Background 2 No Black #410
 Noise  CC 0

Prismatic Geometric Pattern Background 2 No Black

Source GDJ

Background pattern 215 (colour 4) #2368
 Green  CC 0

A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.

Source Firkin

Colourful background #2007
 Colorful  CC 0

Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic

Source Firkin

Colourful bricks pattern (no background) #265
 Noise  CC 0

Original minus the background

Source Firkin

Prismatic Groovy Concentric Background 3@2X #458
 Noise  CC 0

Prismatic Groovy Concentric Background 3

Source GDJ

Dark Mosaic@2X #122
 Dark  CC BY-SA 3.0

Small dots with minor circles spread across to form a nice mosaic.

Source John Burks

Dark Leather #129
 Dark  CC BY-SA 3.0

You were craving more leather, so I whipped this up by scanning a leather jacket.

Source Atle Mo

Background pattern 336 #1721
 Pink  CC 0

Formed by distorting the inside front cover of 'Diversæ insectarum volatilium : icones ad vivum accuratissmè depictæ per celeberrimum pictorem', Jacob Hoefnagel, 1630.

Source Firkin