Small Crackle Bright@2X #353
 Light  CC BY-SA 3.0

Light gray pattern with an almost wall tile-like appearance.

Source Markus Tinner

 More Textures
Rocky Wall #41
 Wall  CC BY-SA 3.0

High detail stone wall with minor cracks and specks.

Source Projecteightyfive

Background pattern 6 #226
 Noise  CC 0

A pattern derived from part of a fractal rendering in Paint.net.

Source Firkin

Prismatic Abstract Geometric Background 4 No Black@2X #442
 Dark  CC 0

Prismatic Abstract Geometric Background 4 No Black

Source GDJ

Zig-zag pattern 4 #2415
 Grid  CC 0

A seamless pattern based on a rectangular tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.

Source Firkin

Background pattern 250 #2172
 Dark  CC 0

To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.

Source Firkin

Seamless Core Pattern 6 #170
 Dark  CC 0

Seamless Core Pattern 6

Source GDJ

Background pattern 2 #221
 Noise  CC 0

A pattern derived from repeating unit cells each derived from part of a fractal rendering in paint.net.

Source Firkin

Background pattern 8 (colour) #211
 Noise  CC 0

Colour version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net

Source Firkin

Prismatic Groovy Concentric Background #449
 Noise  CC 0

Prismatic Groovy Concentric Background

Source GDJ

Cardboard@2X #279
 Paper  CC BY-SA 3.0

A good starting point for a cardboard pattern. This would work well in a variety of colors.

Source Atle Mo