Retro Circles Background 5 #424
 Noise  CC 0

Retro Circles Background 5

Source GDJ

 More Textures
Gun Metal #360
 Dark  CC BY-SA 3.0

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

Source Nikolay Boltachev

Background pattern 277 #2029
 Dark  CC 0

A background pattern inspired by designs seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.

Source Firkin

Background pattern 224 (colour 5) #2338
 Colorful  CC 0

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

Source Firkin

Prismatic Dots Background 3 #505
 Noise  CC 0

Prismatic Dots Background 3

Source GDJ

Background pattern 104 #561
 Dark  CC 0

Background pattern 104

Source Firkin

Background pattern 29 #200
 Dark  CC 0

Pattern produced in Paint.net using the Vibrato plug-in.

Source Firkin

Retro Squares Background 4@2X #419
 Dark  CC 0

Retro Squares Background 4

Source GDJ

Black Linen 2@2X #104
 Dark  CC BY-SA 3.0

A new take on the black linen pattern. Softer this time.

Source Atle Mo

Background pattern 225 #2327
 Colorful  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

Cardboard@2X #279
 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

Prismatic Abstract Geometric Background #269
 Noise  CC 0

Prismatic Abstract Geometric Background derived from an image on Pixabay.

Source GDJ