Dark pattern with some nice diagonal stitched lines crossing over.
Source Ashton
Got some felt in my mailbox today, so I scanned it for you to use.
Source Atle Mo
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
Derived from a PNG that was uploaded to Pixabay by nutkitten
Source Firkin
Background Wall, Art Abstract, Watercolor Vintage style CC0 texture.
Source Ractapopulous
You guessed it – looks a bit like cloth.
Source Peax Webdesign
A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).
Source GDJ
From a drawing in 'Two Women in the Klondike', Mary Hitchcock, 1899.
Source Firkin
Zero CC tileable Crackled Cement (streaks) texture, photographed and made by me. CC0
Source Sojan Janso
Seamless tile drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
Produced using the clouds, flames and glass blocks plug-ins in Paint.net and the resulting .PNG vectorised with Vector Magic.
Source Firkin
Looks like an old rug or a computer chip.
Source Patutin Sergey
Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
One more in the line of patterns inspired by Japanese/Asian styles. Smooth.
Source Kim Ruddock
Fake or not, it’s quite luxurious.
Source Factorio.us Collective
A criss-cross pattern similar to one I saw mown into a sports field.
Source Firkin
Seamless Green Tile Background
Source V. Hartikainen
Not a flat you live inside, like in the UK – but a flat piece of cardboard.
Source Appleshadow
A slightly more textured pattern, medium gray. A bit like a potato sack?
Source Bilal Ketab
The image a seamless pattern derived from a weed which I can't identify.The original weed image is from here:https://jp.pinterest.com/pin/500744052301423641/
Source Yamachem