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
Background pattern black and white #2030
 Dark  CC 0

A background pattern inspired by designs seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.

Source Firkin

Felt #300
 Wall  CC BY-SA 3.0

Got some felt in my mailbox today, so I scanned it for you to use.

Source Atle Mo

Triangular Psychosis 4 #236
 Noise  CC 0

A colorful triangular background, variation 4.

Source GDJ

Cubes@2X #134
 Light  CC BY-SA 3.0

This reminds me of Game Cube. A nice light 3D cube pattern.

Source Sander Ottens

Background pattern 112 #263
 Fabric  CC 0

A seamless pattern with a unit cell drawn as a bitmap in Paint.net and vectorized in Vector Magic.

Source Firkin

Background pattern 18 #202
 Dark  CC 0

A seamless pattern the starting point for which was a 'colour modulo' texture in Paint.net.

Source Firkin

Prismatic Polka Dots Mark II 3 No Background@2X #535
 Noise  CC 0

Prismatic Polka Dots Mark II 3 No Background

Source GDJ

Psychedelic Geometric Background #381
 Noise  CC 0

Psychedelic Geometric Background.

Source GDJ

Background pattern 272 (colour 3) #2055
 Red  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