Gradient [email protected] #694
 Grid  CC BY-SA 3.0

It’s big, it’s gradient—and it’s square.

Source Brankic1979

 More Textures
Prismatic Snowflakes Pattern No [email protected] #783
 Light  CC 0

Prismatic Snowflakes Pattern No Background

Source GDJ

Patterned Pale Orange Background #1314
 Orange  CC BY-SA 3.0

You may use it as is, or modify it as you like.

Source V. Hartikainen

Fabric [email protected] #10
 Light  CC BY-SA 3.0

Semi-light fabric pattern made out of random pixels in shades of gray.

Source Atle Mo

Background pattern 308 (colour 6) #1867
 Pink  CC 0

Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.

Source Firkin

blue wave-seigaiha #2535
 Blue  CC 0

The image depicts the Japanese Edo pattern called "seigaiha" or "青海波" meaning "blue -sea- wave".I hope it's suitable for the summer season.

Source Yamachem

Pixel Weave #1154
 Unknow  CC BY-SA 3.0

Clean and crisp lines all over the place. Wrap it up with this one.

Source Dax Kieran

Broken [email protected] #365
 Dark  CC BY-SA 3.0

Beautiful dark noise pattern with some dust and grunge.

Source Vincent Klaiber

Dark [email protected] #818
 Dark  CC BY-SA 3.0

Just to prove my point, here is a slightly modified dark version.

Source Atle Mo

Black Metal Pipes #1089
 Metal  CC BY-SA 3.0

An abstract texture of black metal pipes (seamless).

Source V. Hartikainen

Flourish pattern (colour) #1737
 Yellow  CC 0

Remixed from an image that was uploaded to Pixabay by Pixeline

Source Firkin

Broken Noise #364
 Dark  CC BY-SA 3.0

Beautiful dark noise pattern with some dust and grunge.

Source Vincent Klaiber

Floral design 101 (version 2) #1757
 Green  CC 0

From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.

Source Firkin

Subtle [email protected] #926
 Light  CC BY-SA 3.0

Super subtle indeed, a medium gray pattern with tiny dots in a grid.

Source Designova

Floral background 21 #1785
 Dark  CC 0

From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.

Source Firkin

Background pattern 314 (colour 3) #1837
 Green  CC 0

The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i

Source Firkin

Planks & Wornboards #1350
 Wood  CC 0

CC0 for Free, hope you like it.

Source Yethiel

Prismatic Geometric Tessellation Pattern 3 No [email protected] #556
 Noise  CC 0

Prismatic Geometric Tessellation Pattern 3 No Background

Source GDJ

Stone Wall & Green #1536
 Stone  CC 0

Incoming catena. Stone & well. CC0 texture.

Source Unknow

Colorful Geometric Pattern Background #231
 Noise  CC 0

PDP

Source GDJ

Leafy pattern (colour) #2334
 Fabric  CC 0

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

Source Firkin

White Brushed #1183
 Wall  CC BY-SA 3.0

Brushed aluminum, in a bright gray version. Lovely 2X as well.

Source Andre Schouten

Rough [email protected] #692
 Fabric  CC BY-SA 3.0

The classic 45-degree diagonal line pattern, done right.

Source Jorick van Hees

Desert Camo Print #255
 Fabric  CC 0

Here's a camo print with more tan and less green, such as might be used in a desert scenario. This is tileable, so it can be used as a wallpaper or background.

Source Eady

Grid Paper Background (Blue Gray) #1162
 Grid  CC BY-SA 3.0

A free grid paper background pattern for using on web sites.

Source V. Hartikainen

Back [email protected] #946
 Light  CC BY-SA 3.0

Pixel by pixel, sharp and clean. Very light pattern with clear lines.

Source M.Ashok

Background pattern 208 (colour 2) #2462
 Grid  CC 0

A seamless pattern created from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.

Source Firkin

Background pattern 235 (colour 6) #2250
 Red  CC 0

To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.

Source Firkin

Dark Wall #817
 Dark  CC BY-SA 3.0

Just to prove my point, here is a slightly modified dark version.

Source Atle Mo

Decorative divider 206 #2380
 Dark  CC 0

Derived from a corner decoration itself found as a jpg on Pixabay.

Source Firkin

Black Linen #63
 Dark  CC BY-SA 3.0

In the spirit of WWDC 2011, here is a dark iOS inspired linen pattern.

Source Atle Mo