Tessellation 16 (colour 3) #2213
 Green  CC 0

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

Source Firkin

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

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

Source Caveman

Green Fibers #91
 Dark  CC BY-SA 3.0

The green fibers pattern will work very well in grayscale as well.

Source Matteo Di Capua

Random Grey Variations@2X #70
 Stripes  CC BY-SA 3.0

Stefan is hard at work, this time with a funky pattern of squares.

Source Stefan Aleksić

Prismatic Rounded Squares Grid 4 No Background@2X #492
 Noise  CC 0

Prismatic Rounded Squares Grid 4 No Background

Source GDJ

Background pattern 214 (colour 3) #2375
 Green  CC 0

A seamless chequerboard pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i. Alternative colour scheme.

Source Firkin

Cross pattern (negative) #2332
 Dark  CC 0

A seamless pattern formed from cross 4. To get the original tile select the rectangle in Inkscape and use shift-alt-i.

Source Firkin

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

60º lines@2X #26
 Light  CC BY-SA 3.0

Never out of fashion and so much hotter than the 45º everyone knows, here is a sweet 60º line pattern.

Source Atle Mo

Background pattern 306 (colour 2) #1881
 Colorful  CC 0

Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.

Source Firkin

Dotnoise Light Grey@2X #309
 Wall  CC BY-SA 3.0

Sort of like the back of a wooden board. Light, subtle, and stylish, just the way we like it!

Source Nikolalek

Seamless Prismatic Pythagorean Line Art Pattern No Background #569
 Light  CC 0

Seamless Prismatic Pythagorean Line Art Pattern No Background. A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).

Source GDJ

Project Papper #119
 Paper  CC BY-SA 3.0

Light square grid pattern, great for a “DIY projects” sort of website, maybe?

Source Rafael Almeida

MBossed@2X #194
 Grid  CC BY-SA 3.0

Embossed lines and squares with subtle highlights.

Source Alex Parker

Background pattern 104 #561
 Dark  CC 0

Background pattern 104

Source Firkin