More Textures
Diamond pattern (colour 6) #2280
 Yellow  CC 0

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

Source Firkin

Colorful Stripes Background #400
 Noise  CC 0

Colorful Stripes Background

Source GDJ

Ravenna #354
 Wall  CC BY-SA 3.0

I guess this is inspired by the city of Ravenna in Italy and its stone walls.

Source Sentel

Prismatic Hypnotic Pattern 2 No Background #573
 Noise  CC 0

Prismatic Hypnotic Pattern 2 No Background

Source GDJ

Prismatic Curved Diamond Pattern 3 No Background #162
 Diamond  CC 0

Prismatic Curved Diamond Pattern 3 No Background

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

Prismatic Dots Background 5@2X #510
 Noise  CC 0

Prismatic Dots Background 5

Source GDJ

Background pattern 269 #2062
 Dark  CC 0

A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i

Source Firkin

Prismatic Curved Diamond Pattern 5 No Background@2X #544
 Diamond  CC 0

Prismatic Curved Diamond Pattern 5 No Background

Source GDJ

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

Concrete Wall 3@2X #94
 Light  CC BY-SA 3.0

All good things come in threes, so I give you the third in my little concrete wall series.

Source Atle Mo

Green Dust & Scratches #107
 Wall  CC BY-SA 3.0

Snap! It’s a pattern, and it’s not grayscale! Of course you can always change the color in Photoshop.

Source Atle Mo

White carbon #11
 Carbon  CC BY-SA 3.0

Same as the black version, but now in shades of gray. Very subtle and fine grained.

Source Atle Mo

Handmade Paper@2X #38
 Paper  CC BY-SA 3.0

White handmade paper pattern with small bumps.

Source Marquis