Glass block pattern #2477
 Brown  CC 0

Produced using the clouds, flames and glass blocks plug-ins in Paint.net and the resulting .PNG vectorised with Vector Magic.

Source Firkin

 More Textures
Gun Metal@2X #361
 Dark  CC BY-SA 3.0

With a name this awesome, how can I go wrong?

Source Nikolay Boltachev

Always Grey #53
 Dark  CC BY-SA 3.0

Crossing lines with a subtle emboss effect on a dark background.

Source Stefan Aleksić

Tessellation 15 #2223
 Dark  CC 0

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

Source Firkin

Lego background #266
 Noise  CC 0

Background formed from the iconic plastic construction bricks that gave me endless hours of fun when I was a lad.

Source Firkin

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

Zig-zag pattern 4 #2415
 Grid  CC 0

A seamless pattern based on a rectangular tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.

Source Firkin

Prismatic Snowflakes Pattern 3 No Background #413
 Light  CC 0

Prismatic Snowflakes Pattern 3 No Background

Source GDJ

Background pattern 263 #2073
 Pink  CC 0

Actually remixed from a pattern on Pixabay. But then noticed a very similar one on Openclipart.org uploaded by btj51q2.

Source Firkin

Dark Leather@2X #130
 Dark  CC BY-SA 3.0

You were craving more leather, so I whipped this up by scanning a leather jacket.

Source Atle Mo

Soft Wallpaper@2X #96
 Wall  CC BY-SA 3.0

Coming in at 666x666px, this is an evil big pattern, but nice and soft at the same time.

Source Atle Mo

"Dark Brick Wall", Background Pattern #1024
 Stone  CC BY-SA 3.0

Like the name suggests, this background image consists of a pattern of dark bricks. It may be an option for you, if you are looking for something that looks like a brick wall for use as a background on web pages. It's not a masterpiece, but looks pretty nice when is tiled.

Source V. Hartikainen

Pool Table #175
 Wall  CC BY-SA 3.0

This makes me wanna shoot some pool! Sweet green pool table pattern.

Source Caveman

Background pattern 201 #2501
 Grid  CC 0

A pattern formed from a squared tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.

Source Firkin