More Textures
Transparent Square Tiles #298
 Grid  CC BY-SA 3.0

The first pattern on here using opacity. Try it on a site with a colored background, or even using mixed colors.

Source Nathan Spady

Prismatic Groovy Concentric Background 4@2X #462
 Noise  CC 0

Prismatic Groovy Concentric Background 4

Source GDJ

Retro Circles Background 4 No Black #422
 Dark  CC 0

Retro Circles Background 4 No Black

Source GDJ

Background2@2X #477
 Wall  CC 0

rug texture background

Source Jilllio

Old Mathematics@2X #44
 Stripes  CC BY-SA 3.0

This one takes you back to math class. Classic mathematic board underlay.

Source Josh Green

Iron Grip@2X #588
 Dark  CC BY-SA 3.0

Sounds like something from World of Warcraft. Has to be good.

Source Tony Kinard

Paisley Background #495
 Light  CC 0

Paisley Background

Source GDJ

Leather 1 #13
 Light  CC BY-SA 3.0

A leather pattern with a hint of yellow.

Source Atle Mo

Prismatic Curved Diamond Pattern 6 No Background #545
 Dark  CC 0

Prismatic Curved Diamond Pattern 6 No Background

Source GDJ

Darth Stripe #99
 Dark  CC BY-SA 3.0

Diagonal lines with a lot of texture to them.

Source Ashton

Prismatic Groovy Concentric Background 3 No Black@2X #460
 Noise  CC 0

Prismatic Groovy Concentric Background 3 No Black

Source GDJ