seigaiha subtle color #2278
 Pink  CC 0

This is a remix of "blue wave-seigaiha".I hope this subtle color version of Seigaiha would be suitable for background .

Source Yamachem

 More Textures
Mirrored Squares #123
 Dark  CC BY-SA 3.0

Did some testing with Repper Pro tonight, and this gray mid-tone pattern came out.

Source Atle Mo

Retro Circles Background 7@2X #432
 Unknow  CC 0

Retro Circles Background 7

Source GDJ

Polonez Pattern@2X #335
 Gray  CC BY-SA 3.0

A car pattern?! Can it be subtle? I say yes!

Source Radosław Rzepecki

Triangles #127
 Dark  CC BY-SA 3.0

Dark and hard, just the way we like it. Embossed triangles makes a nice pattern.

Source Ivan Ginev

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

Soft Kill #318
 Dark  CC BY-SA 3.0

Pattern #100! A black classic knit-looking pattern.

Source Factorio.us Collective