Brushed Aluminum #1388
 Metal  CC 0

Gamedev - Metal Textures. CC0 License.

Source Davit Masia

 More Textures
Wavy background #2019
 Colorful  CC 0

CC0 and a seamless pattern from a tile drawn in Paint.net .

Source SliverKnight

Classy [email protected] #612
 Dark  CC BY-SA 3.0

This is lovely, just the right amount of subtle noise, lines and textures.

Source Richard Tabor

Concretia 9 #1416
 Gray  CC 0

Gamedev - Concrete Textures. CC0 License.

Source Davit Masia

Retro Circles Background [email protected] #436
 Dark  CC 0

Retro Circles Background 8

Source GDJ

Brushed Aluminum 4 #1392
 Metal  CC 0

Gamedev - Metal Textures. CC0 License.

Source Davit Masia

Green Cup #1211
 Unknow  CC BY-SA 3.0

I scanned a paper coffee cup. You know, in case you need it.

Source Atle Mo

Maze [email protected] #1047
 Light  CC BY-SA 3.0

Just like the black maze, only in light gray. Duh.

Source Peax

Background pattern 224 (colour 5) #2338
 Colorful  CC 0

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

Source Firkin

White Texture #131
 Light  CC BY-SA 3.0

Not the most creative name, but it’s a good all-purpose light background.

Source Dmitry

Fabric (Plaid) #591
 Fabric  CC BY-SA 3.0

You know you can’t get enough of these linen-fabric-y patterns.

Source James Basoo

Checkered Light Emboss #280
 Grid  CC BY-SA 3.0

Sort of like the Photoshop transparent background, but better!

Source Alex Parker

Tree and bird pattern #1983
 Dark  CC 0

From a drawing in 'Line and form', Walter Crane, 1914.

Source Firkin

Paven #296
 Grid  CC BY-SA 3.0

A subtle shadowed checkered pattern. Increase the lightness for even more subtle sexiness.

Source Josh Green

Seamless Marble Like Texture (Light Blue) #1033
 Stone  CC BY-SA 3.0

A seamless marble-like texture colored in light blue.

Source V. Hartikainen

Subtle [email protected] #950
 Dark  CC BY-SA 3.0

There are many carbon patterns, but this one is tiny.

Source Designova

Shine [email protected] #714
 Grid  CC BY-SA 3.0

It’s like Shine Dotted’s sister, only rotated 45 degrees.

Source mediumidee

Fabric pattern (colour 5) #2398
 Fabric  CC 0

Alternative colour scheme. Not a pattern for fabrics, but one produced from a jpg of a stack of fabric items that was posted on Pixabay. The tile that this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.

Source Firkin

Rough Fabric Pattern (Dark Brown) #1166
 Fabric  CC BY-SA 3.0

A background pattern with a look of rough fabric.

Source V. Hartikainen

Prismatic Abstract Background Design #403
 Noise  CC 0

Prismatic Abstract Background Design

Source GDJ

Seamless Canvas (Pale Brown) #1165
 Fabric  CC BY-SA 3.0

A seamless canvas texture for using as background on websites. Colored in pale tones of brown.

Source V. Hartikainen

Black Linen 2 #103
 Dark  CC BY-SA 3.0

A new take on the black linen pattern. Softer this time.

Source Atle Mo

Pattern cleanup filtered 2 #152
 Noise  CC 0

Cleanup with gradients and filtering.

Source Lazur URH

Bedge [email protected] #979
 Paper  CC BY-SA 3.0

A large (588x375px) sand-colored pattern for your ever-growing collection. Shrink at will.

Source Alex Tapein

Rice [email protected] #339
 Paper  CC BY-SA 3.0

Scanned some rice paper and tiled it up for you. Enjoy.

Source Atle Mo

Prismatic Hexagonalism Pattern No [email protected] #803
 Light  CC 0

Prismatic Hexagonalism Pattern No Background

Source GDJ

Prismatic Abstract Geometric Background 4 #271
 Noise  CC 0

Prismatic Abstract Geometric Background 4

Source GDJ

Diamonds #1674
 Paper  CC 0

Paper-Wallpaper. CC0 License.

Source Unknow

Psychedelic Geometric Background #381
 Noise  CC 0

Psychedelic Geometric Background.

Source GDJ

Debut [email protected] #1015
 Dark  CC BY-SA 3.0

Same classic 45-degree pattern, dark version.

Source Luke McDonald

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