Not a flat you live inside, like in the UK – but a flat piece of cardboard.
Source Appleshadow
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
A seamless pattern recreated from an image on Pixabay. It is reminiscent of parquet flooring and is formed from a square tile, which can be recovered in Inkscape by selecting the ungrouped rectangle and using shift-alt-I together.
Source Firkin
This background pattern has futuristic look. So, maybe it could be used on websites or blogs dedicated to video games?!
Source V. Hartikainen
Love the style on this one, very fresh. Diagonal diamond pattern. Get it?
Source INS
Some dark 45 degree angles creating a nice pattern. Huge.
Source Dark Sharp Edges
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
The image depicts a shell seamless pattern.I used an OCAL clipart called "Shell" uploaded by "jgm104".Thanks.
Source Yamachem
This was formed by distorting an image of a background on Pixabay.
Source Firkin
Formed by distorting the inside front cover of 'Diversæ insectarum volatilium : icones ad vivum accuratissmè depictæ per celeberrimum pictorem', Jacob Hoefnagel, 1630.
Source Firkin
A free seamless background with pink spots.
Source V. Hartikainen
Prismatic Rounded Squares Grid 4 No Background
Source GDJ
That’s what it is, a dark dot. Or sort of carbon looking.
Source Tsvetelin Nikolov
Dark pattern with some nice diagonal stitched lines crossing over.
Source Ashton
This background texture resembles stone. It may be used as a background on web pages or on some of their html elements (header, borders, menu bar, etc.). Just modify it for your needs.
Source V. Hartikainen
Paper model of a tetrahedron. Modelo de papel de um tetraedro.
Source laobc
Feel free to use this seamless background texture as a background on a web site. It's colored in a light pink color and is seamlessly tile-able.
Source V. Hartikainen
Submitted as a black pattern, I made it light and a few steps more subtle.
Source Andy
Real snow that tiles, not easy. This is not perfect, but an attempt.
Source Atle Mo
Prismatic Triangular Background Design Mark II 5
Source GDJ
More bright luxury. This is a bit larger than fancy deboss, and with a bit more noise.
Source Viszt Péter
Bigger is better, right? So here you have some large carbon fiber.
Source Factorio.us Collective
A seamless pattern formed from cross 4. To get the original tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin