Micro Carbon@2X #8
 Carbon  CC BY-SA 3.0

Three shades of gray makes this pattern look like a small carbon fiber surface. Great readability even for small fonts.

Source Atle Mo

 More Textures
Decorative divider 232 #2148
 Dark  CC 0

From a design found in 'History of the Virginia Company of London; with letters to and from the first Colony, never before printed', Edward Neill, 1869.

Source Firkin

Candyhole #356
 Light  CC BY-SA 3.0

It’s a hole, in a pattern. On your website. Dig it!

Source Josh Green

Prismatic Groovy Concentric Background 2 No Black #455
 Noise  CC 0

Prismatic Groovy Concentric Background 2 No Black

Source GDJ

"Maple", Seamless Wood Texture #883
 Wood  CC BY-SA 3.0

Here I have tried to create something that would look like maple wood. Not sure how well it's turned out, but at least it looks like wood.

Source V. Hartikainen

White Paperboard@2X #375
 Fabric  CC BY-SA 3.0

Could be paper, could be a Polaroid frame – up to you!

Source Chaos

Seamless 3D Isometric Tessellation Pattern 2 #147
 Light  CC 0

A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).

Source GDJ

Project Papper@2X #120
 Paper  CC BY-SA 3.0

Light square grid pattern, great for a “DIY projects” sort of website, maybe?

Source Rafael Almeida

Fleurs-de-lys pattern 2 (colour) #2204
 Colorful  CC 0

Colour version of the original pattern inspired by the front cover of 'Old and New Paris', Henry Edwards, 1894.

Source Firkin

Grunge Wall #81
 Wall  CC BY-SA 3.0

Light gray grunge wall with a nice texture overlay.

Source Adam Anlauf

"Grunge-Like" Background Pattern #1126
 Grunge  CC BY-SA 3.0

Background pattern made in "Grunge-Like" style. Available in both SVG and JPG formats. Edit to your needs then click the download button.

Source V. Hartikainen

Seamless Core Pattern #165
 Dark  CC 0

Seamless Core Pattern

Source GDJ

Noise Pattern With Subtle Cross Lines@2X #180
 Grid  CC BY-SA 3.0

More bright luxury. This is a bit larger than fancy deboss, and with a bit more noise.

Source Viszt Péter

Prismatic Groovy Concentric Background 5 No Black@2X #468
 Dark  CC 0

Prismatic Groovy Concentric Background 5 No Black

Source GDJ

Background pattern 105@2X #564
 Dark  CC 0

A seamless pattern formed from background pattern 102

Source Firkin

Brushed Alum@2X #68
 Light  CC BY-SA 3.0

A light brushed aluminum pattern for your pleasure.

Source Tim Ward

Tessellation 16 #2215
 Yellow  CC 0

The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.

Source Firkin