Not a flat you live inside, like in the UK – but a flat piece of cardboard.
Source Appleshadow
Use shift+alt+i on the selected rectangle in Inkscape to get the tile this is based on
Source Firkin
Prismatic Abstract Geometric Background 5 No Black
Source GDJ
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
Derived from elements found in a floral ornament drawing on Pixabay.
Source Firkin
Prismatic Hypnotic Pattern No Background
Source GDJ
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
Classic 45-degree pattern, light version.
Source Luke McDonald
People seem to enjoy dark patterns, so here is one with some circles.
Source Atle Mo
Light gray paper pattern with small traces of fiber and some dust.
Source Atle Mo
From a drawing in 'From Snowdon to the Sea. Striking stories of North and South Wales', Marie Trevelyan, 1895.
Source Firkin
Three shades of gray makes this pattern look like a small carbon fiber surface. Great readability even for small fonts.
Source Atle Mo
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
The image is a remix of "edo pattern-samekomon".I changed the color of dots from black to white and added BG in light-brown.
Source Yamachem
Prismatic Curved Diamond Pattern 8 No Background
Source GDJ
This is the remix of "Tileable Wave Pattern 2" uploaded by "Arvin61r58".Thanks.I added a wire-mesh fence seamless pattern as a lower layer.
Source Yamachem
The rectangular tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
From a drawing in 'Two Women in the Klondike', Mary Hitchcock, 1899.
Source Firkin
Background formed from the original with an emboss effect
Source GDJ
A repeating gloomy background image. This one consists of a pattern of black chains layered on top of a dark textured background.
Source V. Hartikainen
Luxury pattern, looking like it came right out of Paris.
Source Daniel Beaton
An orange vertically striped background pattern. Feel free to download and use this orange background pattern, for example, on the web). It resembles a wallpaper with vertical stripes or something similar to it.
Source V. Hartikainen
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin