Decorative divider 293 #1752
 Dark  CC 0

From a drawing in 'An Old Maid's Love. A Dutch tale told in English', Maarten Maartens, 1891.

Source Firkin

 More Textures
Mirrored Squares #123
 Dark  CC BY-SA 3.0

Did some testing with Repper Pro tonight, and this gray mid-tone pattern came out.

Source Atle Mo

Prismatic Curved Diamond Pattern No Background #536
 Diamond  CC 0

Prismatic Curved Diamond Pattern No Background

Source GDJ

Abstract Tiled Background Extended 7 #518
 Dark  CC 0

Abstract Tiled Background Extended 7

Source GDJ

Micro Carbon #7
 Carbon  CC BY-SA 3.0

Three shades of gray makes this pattern look like a small carbon fiber surface. Great readability even for small fonts.

Source Atle Mo

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

Broken Noise #364
 Dark  CC BY-SA 3.0

Beautiful dark noise pattern with some dust and grunge.

Source Vincent Klaiber

Abstract Ellipses Background #275
 Dark  CC 0

Abstract Ellipses Background

Source GDJ

Prismatic Groovy Concentric Background 4 No Black #463
 Noise  CC 0

Prismatic Groovy Concentric Background 4 No Black

Source GDJ

Background pattern 239 #2217
 Red  CC 0

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

Source Firkin

White Diamond #366
 Diamond  CC BY-SA 3.0

To celebrate the new feature, we need some sparkling diamonds.

Source Atle Mo

Seamless Wood Pattern #889
 Wood  CC BY-SA 3.0

A seamlessly repeating background pattern of wood. The image is procedurally generated, and, I think, it's turned out quite well.

Source V. Hartikainen

Robots #125
 Dark  CC BY-SA 3.0

And some more testing, this time with Seamless Studio. It’s Robots FFS!

Source Seamless Studio