Dare I call this a «flat pattern»? Probably not.
Source Dax Kieran
Sort of reminds me of those old house wallpapers.
Source Tish
A slightly more textured pattern, medium gray. A bit like a potato sack?
Source Bilal Ketab
I skipped number 3, because it wasn’t all that great. Sorry.
Source Dima Shiper
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 version without colours blended together to give a different look.
Source Firkin
A background pattern with wavy green vertical stripes. This one has green stripes on a white background. Download if you like it.
Source V. Hartikainen
Sort of reminds me of those old house wallpapers.
Source Tish
This one could be the shirt of a golf player. Angled lines in different thicknesses.
Source Olivier Pineda
Little x’es, noise and all the stuff you like. Dark like a Monday, with a hint of blue.
Source Tom McArdle
This was formed by distorting an image of a background on Pixabay.
Source Firkin
Psychedelic Geometric Background No Black
Source GDJ
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
The tile this is formed from can be retrieved in Inkscape by selecting the rectangle and using shift+alt+i
Source Firkin
You can never get enough of these tiny pixel patterns with sharp lines.
Source Designova
Dark wooden pattern, given the subtle treatment. based on texture from Cloaks.
The texture of this background image has some similarities with leather, and it's colored in a dark brown color. So, if you are looking for a dark brown background image for your website, this may be an option for you.
Source V. Hartikainen
Prismatic Curved Diamond Pattern 5 No Background
Source GDJ