This could be a hippy vintage wallpaper.
Source Tileable Patterns
Prismatic Curved Diamond Pattern 4 No Background
Source GDJ
A free grid paper background pattern for using on web sites.
Source V. Hartikainen
This is so subtle I hope you can see it! Tweak at will.
Source Alexandre Naud
A simple but elegant classic. Every collection needs one of these.
Source Christopher Burton
A seamless pattern created from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Abstract Ellipses Background Grayscale
Source GDJ
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
Inspired by a pattern found in 'A General History of Hampshire, or the County of Southampton, including the Isle of Wight', Bernard Woodwood, 1861
Source Firkin
A seamless stone-like background for blogs or any other type of websites.
Source V. Hartikainen
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
This is the remix of "blue wave-seigaiha".The image depicts a seamless pattern of the front upper part of Japanese five yen coin which is used currently.This design represents a rice with ripe golden ears.
Source Yamachem
Prismatic Floral Pattern 3 Variation 3 No Background
Source GDJ
It was called Navy Blue, but I made it dark. You know, the way I like it.
Source Ethan Hamilton
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
Clover with background for St. Patrick's Day. Add to a card with a doily, ribbon, a leprechaun or other embellishments.
Source BAJ
This light background pattern has a texture of "frozen" surface with diagonal stripes. Here's an yet another addition to the collection of free website backgrounds.
Source V. Hartikainen
Prismatic Polka Dots 3 No Background
Source GDJ
The tile this is formed from can be retrieved in Inkscape by selecting the rectangle and using shift+alt+i
Source Firkin
This seamless background image should look nice on websites. It has a dark blue gray texture with vertical stripes, it tiles seamlessly and, like all of the background images here, it's free. So, if you like it, take it!
Source V. Hartikainen
Three shades of gray makes this pattern look like a small carbon fiber surface. Great readability even for small fonts.
Source Atle Mo