You may use it as is, or modify it as you like.
Source V. Hartikainen
Dark and hard, just the way we like it. Embossed triangles makes a nice pattern.
Source Ivan Ginev
Small dots with minor circles spread across to form a nice mosaic.
Source John Burks
Prismatic Polka Dots Mark II No Background
Source GDJ
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i
Source Firkin
A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.
Source Firkin
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
This was formed by distorting an image of a background on Pixabay.
Source Firkin
A version without colours blended together to give a different look.
Source Firkin
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
Could be paper, could be a Polaroid frame – up to you!
Source Chaos
The first pattern on here using opacity. Try it on a site with a colored background, or even using mixed colors.
Source Nathan Spady
All good things come in threes, so I give you the third in my little concrete wall series.
Source Atle Mo
Remixed from a drawing in 'A Child of the Age', Francis Adams, 1894.
Source Firkin
I guess this one is inspired by an office. A dark office.
Source Andrés Rigo.
Bright Multicolored Floral Background by Karen Arnold from PDP.
Source GDJ
Prismatic Abstract Geometric Background 5
Source GDJ
Seamless pattern the basic tile for which can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
After 1 comes 2, same but different. You get the idea.
Source Hendrik Lammers
Inspired by a design found in 'Konstantinápolyi emlékeim', Miklos Chriszto, 1893.
Source Firkin
The tile this is based on can be retrieved by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin