Not a flat you live inside, like in the UK – but a flat piece of cardboard.
Source Appleshadow
A new take on the black linen pattern. Softer this time.
Source Atle Mo
Remixed from a drawing in 'Hungary. A guide book. By several authors', 1890.
Source Firkin
Here's a camo print with more tan and less green, such as might be used in a desert scenario. This is tileable, so it can be used as a wallpaper or background.
Source Eady
Bigger is better, right? So here you have some large carbon fiber.
Source Factorio.us Collective
If you’re sick of the fancy 3D, grunge and noisy patterns, take a look at this flat 2D brick wall.
Source Listvetra
A free pink background pattern.
Source V. Hartikainen
A new one called white wall, not by me this time.
Source Yuji Honzawa
Remixed from a raster on Pixabay, that was uploaded by ArtsyBee.
Source Firkin
Prismatic Curved Diamond Pattern No Background
Source GDJ
A very dark asfalt pattern based off of a photo taken with my iPhone.
Source Atle Mo
A bit like smudged paint or some sort of steel, here is scribble light.
Source Tegan Male
A seamless dark leather-like background texture with diagonal lines that look like stitches.
Source V. Hartikainen
A seamless pattern the starting point for which was a 'light rays' rendering in Paint.net.
Source Firkin
Alternative colour scheme. Not a pattern for fabrics, but one produced from a jpg of a stack of fabric items that was posted on Pixabay. The tile that this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
I love cream! 50x50px and lovely in all the good ways.
Source Thomas Myrman
Number 3 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A background pattern with a look of rough fabric.
Source V. Hartikainen
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Colour version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin