Background pattern 236 #2249
 Dark  CC 0

Seamless pattern the basic tile for which can be had by selecting the rectangle in Inkscape and using shift+alt+i.

Source Firkin

 More Textures
Prismatic Polka Dots Mark II 3 No Background #534
 Noise  CC 0

Prismatic Polka Dots Mark II 3 No Background

Source GDJ

Always Grey #53
 Dark  CC BY-SA 3.0

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

Source Stefan Aleksić

Background pattern 227 (colour 2) #2313
 Blue  CC 0

A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.

Source Firkin

Prismatic Polka Dots Mark II 2 No Background #532
 Noise  CC 0

Prismatic Polka Dots Mark II 2 No Background

Source GDJ

Cardboard #278
 Paper  CC BY-SA 3.0

A good starting point for a cardboard pattern. This would work well in a variety of colors.

Source Atle Mo

Background pattern 265 #2081
 Dark  CC 0

Remixed from a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892. The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i

Source Firkin

Retro Squares Background 8 #398
 Noise  CC 0

Retro Squares Background 8

Source GDJ

Background pattern 333 #1741
 Noise  CC 0

The tile this is formed from can be retrieved in Inkscape by selecting the rectangle and using shift+alt+i

Source Firkin

Background pattern 19 (black) #203
 Dark  CC 0

A seamless pattern the starting point for which was a 'rainbow twist' texture in Paint.net.

Source Firkin

Decorative divider 228 #2154
 Dark  CC 0

Remixed from a design found in 'History of the Virginia Company of London; with letters to and from the first Colony, never before printed', Edward Neill, 1869.

Source Firkin

Gun Metal@2X #361
 Dark  CC BY-SA 3.0

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

Source Nikolay Boltachev