Squares #302
 Dark  CC BY-SA 3.0

Dark, square, clean and tidy. What more can you ask for?

Source Jaromír Kavan

 More Textures
White Sand #19
 Light  CC BY-SA 3.0

Same as gray sand but lighter. A sandy pattern with small light dots, and some angled strokes.

Source Atle Mo

Polonez Pattern #334
 Gray  CC BY-SA 3.0

A car pattern?! Can it be subtle? I say yes!

Source Radosław Rzepecki

Background pattern 105 #563
 Dark  CC 0

A seamless pattern formed from background pattern 102

Source Firkin

Tactile Noise #5
 Dark  CC BY-SA 3.0

A heavy dark gray base, some subtle noise and a 45-degree grid makes this look like a pattern with a tactile feel to it.

Source Atle Mo

Ribbon pattern 2 (version 2) #2039
 Colorful  CC 0

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

Source Firkin

Retro Circles Background 5 No Black #426
 Noise  CC 0

Retro Circles Background 5 No Black

Source GDJ

Prismatic Triangular Seamless Pattern III With Background #273
 Dark  CC 0

Prismatic Triangular Seamless Pattern III With Background

Source GDJ

Background pattern 269 #2062
 Dark  CC 0

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

Source Firkin

Diamond pattern 2 (colour 5) #2264
 Blue  CC 0

From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.

Source Firkin