This is so subtle I hope you can see it! Tweak at will.
Source Alexandre Naud
An emulated “transparent” background pattern, like that of all kinds of computer graphics software.
Source AdamStanislav
A free seamless background with pink spots.
Source V. Hartikainen
The image depicts a seamless pattern of a fishnet with a plenty of fish.It may be a lucky charm for fishermen.
Source Yamachem
Prismatic Groovy Concentric Background 5
Source GDJ
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857. The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin