More Textures
WaveCut #75
 Light  CC BY-SA 3.0

If you like it a bit trippy, this wave pattern might be for you.

Source Ian Soper

Diamond pattern 2 (colour 3) #2266
 Colorful  CC 0

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

Source Firkin

My Little Plaid #332
 Light  CC BY-SA 3.0

Repeating squares overlapping.

Source Pete Fecteau

Stripy checkerboard pattern 2 #1767
 Dark  CC 0

Simple combination of stripy squares with their negatively coloured counterparts

Source Firkin

Zig-zag pattern 6 #2413
 Grid  CC 0

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

Source Firkin

Inflicted #117
 Grid  CC BY-SA 3.0

Dark squares with some virus-looking dots in the grid.

Source Hugo Loning

Grunge Wall@2X #82
 Wall  CC BY-SA 3.0

Light gray grunge wall with a nice texture overlay.

Source Adam Anlauf

Colourful bricks pattern (no background) #265
 Noise  CC 0

Original minus the background

Source Firkin

Prismatic Curved Diamond Pattern No Background@2X #537
 Diamond  CC 0

Prismatic Curved Diamond Pattern No Background

Source GDJ

Micro Carbon #7
 Carbon  CC BY-SA 3.0

Three shades of gray makes this pattern look like a small carbon fiber surface. Great readability even for small fonts.

Source Atle Mo

Ravenna@2X #355
 Wall  CC BY-SA 3.0

I guess this is inspired by the city of Ravenna in Italy and its stone walls.

Source Sentel