Concrete Wall #77
 Wall  CC BY-SA 3.0

Dark blue concrete wall with some small dust spots.

Source Atle Mo

 More Textures
Background pattern 104@2X #562
 Dark  CC 0

Background pattern 104

Source Firkin

Shapes pattern #2409
 Brown  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

Black Paper #55
 Dark  CC BY-SA 3.0

Black paper texture, based on two different images.

Source Atle Mo
Based from Design Kindle

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 Geometric Tessellation Pattern 2 No Background@2X #554
 Noise  CC 0

Prismatic Geometric Tessellation Pattern 2 No Background

Source GDJ

Robots@2X #126
 Dark  CC BY-SA 3.0

And some more testing, this time with Seamless Studio. It’s Robots FFS!

Source Seamless Studio

Prismatic Abstract Line Art Pattern Background 2 #567
 Dark  CC 0

Prismatic Abstract Line Art Pattern Background 2

Source GDJ

Beige Paper #83
 Paper  CC BY-SA 3.0

This was submitted in a beige color, hence the name. Now it’s a gray paper pattern.

Source Konstantin Ivanov

Floral pattern 15 #1753
 Dark  CC 0

The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i

Source Firkin

Prismatic Dots Background 5@2X #510
 Noise  CC 0

Prismatic Dots Background 5

Source GDJ

Colorful Geometric Pattern Background #231
 Noise  CC 0

PDP

Source GDJ