More Textures
Prismatic Abstract Geometric Background 3 #270
 Noise  CC BY-SA 3.0

Prismatic Abstract Geometric Background 3

Source GDJ

Carbon Fiber@2X #4
 Carbon  CC BY-SA 3.0

A dark pattern made out of 3×3 circles and a 1px shadow. This works well as a carbon texture or background.

Source Atle Mo

Abstract Tiled Background Extended 7 #518
 Dark  CC 0

Abstract Tiled Background Extended 7

Source GDJ

Decorative divider 250 #2070
 Dark  CC 0

Remixed from a drawing in 'Очерки Русской Исторіи въ памятникахъ быта', Petr Polevoi, 1879.

Source Firkin

WaveCut@2X #76
 Light  CC BY-SA 3.0

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

Source Ian Soper

Prismatic Groovy Concentric Background 3 #457
 Noise  CC 0

Prismatic Groovy Concentric Background 3

Source GDJ

Tessellation 15 (colour 2) #2221
 Yellow  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

Background pattern 202 #2491
 Brown  CC 0

Based on several public domain drawings on Wikimedia Commons. This was formed from a rectangular tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.

Source Firkin

Background pattern 208 #2465
 Grid  CC 0

A seamless pattern created from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.

Source Firkin

Prismatic Triangular Background Design Mark II 5 #406
 Dark  CC 0

Prismatic Triangular Background Design Mark II 5

Source GDJ

Zig-zag pattern 2 #2417
 Grid  CC 0

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

Source Firkin

Retro Squares Background 9 #399
 Dark  CC 0

Retro Squares Background 9

Source GDJ

Subtle Orange Emboss #97
 Light  CC BY-SA 3.0

A hint of orange color, and some crossed and embossed lines.

Source Adam Anlauf