Remixed from a drawing in 'The March of Loyalty', Letitia MacClintock, 1884.
Source Firkin
This metal background pattern resembles a metal plate with rivets. Solid rivets on a metal plate.
Source V. Hartikainen
This is lovely, just the right amount of subtle noise, lines and textures.
Source Richard Tabor
A bit of scratched up grayness. Always good.
Source Dmitry
This one is something special. I’d call it a flat pattern, too. Very well done, sir!
Source GetDiscount
A free green background pattern with a pattern of rhombuses on a seamless texture. Feel free to use it as a tiled background image on your web site.
Source V. Hartikainen
A browner version of the original weathered fence texture.
Source Firkin
A dark metallic background with a pattern of stamped dots. Here's a dark "metallic" background pattern for you.
Source V. Hartikainen
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
Element of beach pattern with background.
Source Rones
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
First pattern tailor-made for Retina, with many more to come. All the old ones are upscaled, in case you want to re-download.
Source Atle Mo
Prismatic Abstract Geometric Background 4
Source GDJ
Prismatic Geometric Tessellation Pattern 3 No Background
Source GDJ
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
Prismatic Abstract Background Design No Black
Source GDJ
Looks like an old rug or a computer chip.
Source Patutin Sergey
Derived from an image that was uploaded to Pixabay by starchim01
Source Firkin
Prismatic Groovy Concentric Background 2
Source GDJ