Prismatic Dots Background 3 #505
 Noise  CC 0

Prismatic Dots Background 3

Source GDJ

 More Textures
Fake Brick@2X #359
 Dark  CC BY-SA 3.0

Black, simple, elegant, and useful.

Source Marat

Light Aluminum@2X #305
 Wall  CC BY-SA 3.0

Used correctly, this could be nice. Used in a bad way, all hell will break loose.

Source Atle Mo

Background pattern 215 (colour 2) #2370
 Blue  CC 0

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

Source Firkin

Cross pattern #2333
 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

Paper model of a tetrahedron #139
 Unknow  CC 0

Paper model of a tetrahedron. Modelo de papel de um tetraedro.

Source laobc

Background pattern 224 (colour 3) #2340
 Colorful  CC 0

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

Source Firkin

Carbon Fiber v2 #105
 Carbon  CC BY-SA 3.0

One more updated pattern. Not really carbon fiber, but it’s the most popular pattern, so I’ll give you an extra choice.

Source Atle Mo

Bright Squares #87
 Light  CC BY-SA 3.0

It’s okay to be square! A nice light gray pattern with random squares.

Source Waseem Dahman

Diamond pattern (colour 7) #2274
 Red  CC 0

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

Source Firkin