More Textures
Background pattern 239 (colour 2) #2216
 Red  CC 0

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

Source Firkin

Retro Circles Background 4 No Black #422
 Dark  CC 0

Retro Circles Background 4 No Black

Source GDJ

Old Mathematics@2X #44
 Stripes  CC BY-SA 3.0

This one takes you back to math class. Classic mathematic board underlay.

Source Josh Green

Background pattern 215 #2371
 Brown  CC 0

A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.

Source Firkin

Seamless Prismatic Pythagorean Line Art Pattern No Background@2X #570
 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

Beige Paper@2X #84
 Paper  CC BY-SA 3.0

This was submitted in a beige color, hence the name. Now it’s a gray paper pattern.

Source Konstantin Ivanov

Candyhole #356
 Light  CC BY-SA 3.0

It’s a hole, in a pattern. On your website. Dig it!

Source Josh Green

Background pattern 306 (colour 4) #1877
 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

Carbon Fiber Big@2X #327
 Carbon  CC BY-SA 3.0

Bigger is better, right? So here you have some large carbon fiber.

Source Factorio.us Collective

Colorful Geometric Pattern Background #231
 Noise  CC 0

PDP

Source GDJ

Configurable Graph Paper #141
 Stripes  CC BY-SA 3.0

Pass parameters to the URL or edit the source code variables to configure the graph paper for the division desired.

Source JayNick