Stucco #294
 Wall  CC BY-SA 3.0

A nice and simple gray stucco material. Great on its own, or as a base for a new pattern.

Source Bartosz Kaszubowski

 More Textures
Prismatic Geometric Tessellation Pattern 4 No Background #557
 Noise  CC 0

Prismatic Geometric Tessellation Pattern 4 No Background

Source GDJ

Background pattern 202 #2491
 Brown  CC 0

Based on several public domain drawings on Wikimedia Commons. This was formed from a rectangular tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.

Source Firkin

Pool Table@2X #176
 Wall  CC BY-SA 3.0

This makes me wanna shoot some pool! Sweet green pool table pattern.

Source Caveman

Retro Squares Background 5 #395
 Dark  CC 0

Retro Squares Background 5

Source GDJ

"Dark Brick Wall", Background Pattern #1024
 Stone  CC BY-SA 3.0

Like the name suggests, this background image consists of a pattern of dark bricks. It may be an option for you, if you are looking for something that looks like a brick wall for use as a background on web pages. It's not a masterpiece, but looks pretty nice when is tiled.

Source V. Hartikainen

Abstract Ellipses Background Grayscale #378
 Dark  CC 0

Abstract Ellipses Background Grayscale

Source GDJ

Background pattern 104@2X #562
 Dark  CC 0

Background pattern 104

Source Firkin

Noisy #45
 Paper  CC BY-SA 3.0

Looks a bit like concrete with subtle specks spread around the pattern.

Source Mladjan Antic

Decorative divider 252 #2065
 Dark  CC 0

Remix from a drawing in 'Ostatnie chwile powstania styczniowego', Zygmunt Sulima, 1887.

Source Firkin

Prismatic Groovy Concentric Background 2 No Black@2X #456
 Noise  CC 0

Prismatic Groovy Concentric Background 2 No Black

Source GDJ