Green Fibers@2X #92
 Dark  CC BY-SA 3.0

The green fibers pattern will work very well in grayscale as well.

Source Matteo Di Capua

 More Textures
Paper 1 #15
 Paper  CC BY-SA 3.0

A slightly grainy paper pattern with small horizontal and vertical strokes.

Source Atle Mo

Prismatic Dots Background@2X #502
 Noise  CC 0

Prismatic Dots Background

Source GDJ

Decorative divider 289 #1819
 Dark  CC 0

From a drawing in 'Navigations de Alouys de Cademoste.-La Navigation du Capitaine Pierre Sintre', Alvise da ca da Mosto, 1895.

Source Firkin

Silver Scales@2X #190
 Light  CC BY-SA 3.0

Turn your site into a dragon with this great scale pattern.

Source Alex Parker

Pineapple Cut@2X #584
 Diamond  CC BY-SA 3.0

I love the movie Pineapple Express, and I’m also liking this Pineapple right here.

Source Audee Mirza

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

Subtle Freckles #89
 Light  CC BY-SA 3.0

This is so subtle: We’re talking 1% opacity. Get your squint on!

Source Atle Mo

Elastoplast #282
 Light  CC BY-SA 3.0

A fun-looking elastoplast/band-aid pattern. A hint of orange tone in this one.

Source Josh Green

Background pattern 225 (colour 5) #2323
 Blue  CC 0

Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.

Source Firkin

Soft Circle Scales@2X #114
 Light  CC BY-SA 3.0

Japanese looking fish scale pattern.

Source Ian Soper

Prismatic Abstract Geometric Background 5 No Black #402
 Noise  CC 0

Prismatic Abstract Geometric Background 5 No Black

Source GDJ

Decorative divider 194 #2478
 Dark  CC 0

From a drawing in 'Friend or Fortune? The story of a strange year', Robert Overton, 1897.

Source Firkin

Prismatic Floral Background No Black #475
 Light  CC 0

Prismatic Floral Background No Black

Source GDJ