Dare I call this a «flat pattern»? Probably not.
Source Dax Kieran
The base gradient edited so now more details are rendered.
Source Lazur URH
Zero CC bark from fur tree tileable texture, photographed and made by me. CC0
Source Sojan Janso
CC0 remixed from a drawing. Walter Crane, 1914, Firkin.
Source SliverKnight
It’s like Shine Dotted’s sister, only rotated 45 degrees.
Source mediumidee
Traced from a drawing in 'Household Stories from the Collection of the Brothers Grimm', Wilhelm Carl Grimm , 1882.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Dark, square, clean and tidy. What more can you ask for?
Source Jaromír Kavan
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A pattern formed from a squared tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
This is a remix of "blue wave-seigaiha".I hope this subtle color version of Seigaiha would be suitable for background .
Source Yamachem
From a drawing in 'The Quiver of Love', Walter Crane, 1876
Source Firkin
Prismatic Curved Diamond Pattern 8 No Background
Source GDJ
This was formed by distorting an image of a background on Pixabay.
Source Firkin
Drawn in Paint.net using the kaleidoscope plug-in and vectorised.
Source Firkin
A seamless pattern based on a square tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Prismatic Groovy Concentric Background 4 No Black
Source GDJ
I’m starting to think I have a concrete wall fetish.
Source Atle Mo
Did anyone say The Hoff? This pattern is in no way related to Baywatch.
Source Josh Green
An abstract texture of water. It's not perfect, but will do. You may download if you like it.
Source V. Hartikainen
This was formed by distorting an image of a background on Pixabay.
Source Firkin
A dark gray, sandy pattern with small light dots, and some angled strokes.
Source Atle Mo
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin