Background Wall, Art Abstract, Block Well & CC0 texture.
Source Ractapopulous
Inspired by a 1930s wallpaper pattern I saw on TV.
Source Firkin
Not a flat you live inside, like in the UK – but a flat piece of cardboard.
Source Appleshadow
Derived from an image that was uploaded to Pixabay by Kaz
Source Firkin
Otis Ray Redding was an American soul singer-songwriter, record producer, arranger, and talent scout. So you know.
Source Thomas Myrman
Sounds like something from World of Warcraft. Has to be good.
Source Tony Kinard
From a drawing in 'The Quiver of Love', Walter Crane, 1876
Source Firkin
A chequerboard pattern with a fruit theme. The fruits are from a posting by inkscapeforum.it.
Source Firkin
Embossed lines and squares with subtle highlights.
Source Alex Parker
Remixed from a drawing in 'The Canadian horticulturist', 1892
Source Firkin
A light gray wall or floor (you decide) of concrete.
Source Atle Mo
Not strictly seamless in that opposite edges are not identical. But they do marry up to make an interesting pattern
Source Firkin
From a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin
The classic notebook paper with horizontal stripes.
Source Are Sundnes
A seamless pattern from a tile made from a jpg on Pixabay. To get the tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Here's a tile-able wood background image for use in web design.
Source V. Hartikainen
From a drawing in 'Heroes of North African Discovery', Nancy Meugens, 1894.
Source Firkin
Simple wide squares with a small indent. Fits all.
Source Petr Šulc.