Background Patterns - Ebony #249
 Fabric  CC 0

If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117

Source Viscious-Speed

 More Textures
Fabric pattern 3 (colour 5) #2383
 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

Psychedelic Geometric Background No Black #382
 Noise  CC 0

Psychedelic Geometric Background No Black

Source GDJ

Graphene pattern 2 #2234
 Dark  CC 0

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

Source Firkin

3px Tile@2X #343
 Dark  CC BY-SA 3.0

Tiny dark square tiles with varied color tones.

Source Gre3g

Black Mamba #57
 Dark  CC BY-SA 3.0

The name alone is awesome, but so is this sweet dark pattern.

Source Federica Pelzel