Scanned some rice paper and tiled it up for you. Enjoy.
Source Atle Mo
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
A seamless pattern made from the gold Penrose triangle by GDJ and the two remixes
Source Firkin
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
A version without colours blended together to give a different look.
Source Firkin
Simple wide squares with a small indent. Fits all.
Source Petr Šulc.
Prismatic Rounded Squares Grid 3 No Background
Source GDJ
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
From a drawing of the coat of arms of the Ottoman Empire on Wikimedia.
Source Firkin
A slightly more textured pattern, medium gray. A bit like a potato sack?
Source Bilal Ketab
Derived from an image that was uploaded to Pixabay by Darkmoon1968
Source Firkin
Lovely pattern with some good-looking non-random noise lines.
Source Zucx
Pattern #100! A black classic knit-looking pattern.
Source Factorio.us Collective
A very dark asfalt pattern based off of a photo taken with my iPhone.
Source Atle Mo
Small dots with minor circles spread across to form a nice mosaic.
Source John Burks
Snap! It’s a pattern, and it’s not grayscale! Of course you can always change the color in Photoshop.
Source Atle Mo
Square design drawn in Paint.net and vectorized in Vector Magic.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
The act or state of corrugating or of being corrugated, a wrinkle; fold; furrow; ridge.
Source Anna Litvinuk
Derived from a PNG that was uploaded to Pixabay by nutkitten
Source Firkin
Prismatic Curved Diamond Pattern 8 No Background
Source GDJ
Sometimes you just need the simplest thing.
Source Fabricio
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
And some more testing, this time with Seamless Studio. It’s Robots FFS!
Source Seamless Studio
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Everyone loves a diamond, right? Make your site sparkle.
Source AJ Troxell