Project Papper@2X #120
 Paper  CC BY-SA 3.0

Light square grid pattern, great for a “DIY projects” sort of website, maybe?

Source Rafael Almeida

 More Textures
Patern dots #241
 Dark  CC 0

Pattern repeating background 48x48

Source Keistutis

Black Mamba@2X #58
 Dark  CC BY-SA 3.0

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

Source Federica Pelzel

Foggy Birds #579
 Light  CC BY-SA 3.0

Hey, you never know when you’ll need a bird pattern, right?

Source Pete Fecteau

Prismatic Curved Diamond Pattern No Background #536
 Diamond  CC 0

Prismatic Curved Diamond Pattern No Background

Source GDJ

Old Wall@2X #347
 Wall  CC BY-SA 3.0

Old concrete wall in light shades.

Source Bartosz Kaszubowski

Fabric pattern (colour 2) #2401
 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

Carbon Fiber v2@2X #106
 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

samekomon-01 #2270
 Yellow  CC 0

The image is a remix of "edo pattern-samekomon".I changed the color of dots from black to white and added BG in light-yellow.

Source Yamachem

Decorative divider 274 #1922
 Dark  CC 0

Redrawn based on a drawing in 'По Сѣверо-Западу Россіи' Konstantin Sluchevsky, 1897.

Source Firkin

Fire diamond #2488
 Diamond  CC 0

U.S.-based National Fire Protection Association standard fire diamond for flagging risks posed by hazardous materials. The red diamond has a number 0-4 depending on flammability. The blue diamond has a number 0-4 depending on health hazard. The yellow has a number 0-4 depending on reactivity. the white square has a special notice, e.g OX for oxidizer.

Source Firkin