Not a flat you live inside, like in the UK – but a flat piece of cardboard.
Source Appleshadow
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin
Subtle scratches on a light gray background.
Source Andrey Ovcharov
Remixed from a design on Pixabay. To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin
You can never get enough of these tiny pixel patterns with sharp lines.
Source Designova
Formed by heavily distorting part of a an image of a fish uploaded to Pixabay by GLady
Source Firkin
Retro Circles Background 8 No Black
Source GDJ
Derived from a PNG that was uploaded to Pixabay by nutkitten
Source Firkin
You know, tiny and sharp. I’m sure you’ll find a use for it.
Source Atle Mo
One more in the line of patterns inspired by Japanese/Asian styles. Smooth.
Source Kim Ruddock
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Here's an yet another seamless note paper texture for use as a background on websites.
Source V. Hartikainen
From a drawing in 'Less Black than we're painted', James Payn, 1884.
Source Firkin
It’s big, it’s gradient—and it’s square.
Source Brankic1979
Remixed from a drawing in 'The Canadian horticulturist', 1892
Source Firkin
Dark Tile-able Grunge Texture. I think this texture can be classified as grunge. It's free and seamless, as always.
Source V. Hartikainen
From a drawing in 'Resa i Afrika, genom Angola, Ovampo och Damaraland', P. Moller, 1899.
Source Firkin
Smooth Polaroid pattern with a light blue tint.
Source Daniel Beaton
An abstract texture of black metal pipes (seamless).
Source V. Hartikainen
Black & white version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Derived from a JPG that was uploaded to Pixabay by ractapopulous
Source Firkin
Prismatic Isometric Cube Extra Pattern No Background
Source GDJ