This could be a hippy vintage wallpaper.
Source Tileable Patterns
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
This is a semi-dark pattern, sort of linen-y.
Source Sagive SEO
From a drawing in 'Navigations de Alouys de Cademoste.-La Navigation du Capitaine Pierre Sintre', Alvise da ca da Mosto, 1895.
Source Firkin
The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
f you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
Never out of fashion and so much hotter than the 45º everyone knows, here is a sweet 60º line pattern.
Source Atle Mo
A rusty grunge background for websites. Feel free to use it in your site's theme.
Source V. Hartikainen
Prismatic Groovy Concentric Background
Source GDJ
Derived from an image that was uploaded to Pixabay by mdmelo.
Source Firkin
A seamless tessellation pattern. To get the tile this is formed from, select the pattern in Inkscape and use shift+alt+i.
Source Firkin
A large (588x375px) sand-colored pattern for your ever-growing collection. Shrink at will.
Source Alex Tapein
Prismatic Snowflakes Pattern 2 No Background
Source GDJ
Zero CC tileable Crackled Cement (streaks) texture, photographed and made by me. CC0
Source Sojan Janso
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
Number 5 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
A seamless pattern created from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Fake or not, it’s quite luxurious.
Source Factorio.us Collective
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin
A fun-looking elastoplast/band-aid pattern. A hint of orange tone in this one.
Source Josh Green
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin