Not a flat you live inside, like in the UK – but a flat piece of cardboard.
Source Appleshadow
Derived from a JPG that was uploaded to Pixabay by ractapopulous
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i
Source Firkin
Snap! It’s a pattern, and it’s not grayscale! Of course you can always change the color in Photoshop.
Source Atle Mo
From a drawing in 'Cowdray: the history of a great English House', Julia Roundell, 1884.
Source Firkin
A nice looking light gray background pattern with diagonal stripes.
Source V. Hartikainen
The image depicts a seamless pattern of a Japanese family crest called "chidori" in Japanese .A chidori in Japanese means a plover in English.
Source Yamachem
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
This is sort of fresh, but still feels a bit old school.
Source Martuchox
Prismatic Groovy Concentric Background 5 No Black
Source GDJ
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Background pattern originally a PNG drawn in Paint.net
Source Firkin
A seamless background colored in pale orange. It has a paper like texture with diagonal grid pattern.
Source V. Hartikainen
A seamless pattern formed from a square tile based on a jpg on Pixabay. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-I.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
We have some linen patterns here, but none that are stressed. Until now.
Source Jordan Pittman
Light gray pattern with an almost wall tile-like appearance.
Source Markus Tinner
To get the tile this is made up from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Paper pattern with small dust particles and 45-degree strokes.
Source Atle Mo