A simple circle. That’s all it takes. This one is even transparent, for those who like that.
Source Saqib
Crossing lines with a subtle emboss effect on a dark background.
Source Stefan Aleksić
A seamless pattern the starting point for which was a 'colour modulo' texture in Paint.net.
Source Firkin
Three shades of gray makes this pattern look like a small carbon fiber surface. Great readability even for small fonts.
Source Atle Mo
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
I know there is one here already, but this is sexy!
Source Gjermund Gustavsen
Prismatic Groovy Concentric Background 3 No Black
Source GDJ
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
A seamless pattern formed from a rectangular tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
A seamless pattern based on a square tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
ZeroCC tileable stone texture, edited from pixabay. CC0
Source Sojan Janso
Everyone loves a diamond, right? Make your site sparkle.
Source AJ Troxell
It’s okay to be square! A nice light gray pattern with random squares.
Source Waseem Dahman
Derived from a drawing in 'The Murmur of the Shells', Samuel Cowen, 1879.
Source Firkin
Actually remixed from a pattern on Pixabay. But then noticed a very similar one on Openclipart.org uploaded by btj51q2.
Source Firkin
Remixed from a drawing in 'The March of Loyalty', Letitia MacClintock, 1884.
Source Firkin
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
You could get a bit dizzy from this one, but it might come in handy.
Source Dertig Media
I skipped number 3, because it wasn’t all that great. Sorry.
Source Dima Shiper
Classy golf-pants pattern, or crossed stripes if you will.
Source Will Monson
A bit simplified version. Although it could be edited out to be simpler. Anyway, this time the tiling is converted to a pattern fill -which is using clipping for the tile's edges.
Source Lazur URH
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
More Japanese-inspired patterns, Gold Scales this time.
Source Josh Green