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 that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).
Source GDJ
Medium gray fabric pattern with 45-degree lines going across.
Source Atle Mo
Kaleidoscope Prismatic Abstract No Background
Source GDJ
This is so subtle I hope you can see it! Tweak at will.
Source Alexandre Naud
Some more diagonal lines and noise, because you know you want it.
Source Atle Mo
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
Dark wooden pattern, given the subtle treatment. based on texture from Cloaks. https://cloaks.deviantart.com
Source Atle Mo
A free seamless background image with a texture of dark red "canvas". It should look very nice on web sites.
Source V. Hartikainen
This pattern comes in orange, and it looks as if it is "made of glass".
Source V. Hartikainen
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Green Background Pattern
Source V. Hartikainen
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
A seamless pattern formed from a sports car on clker.com. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Colour version of the original pattern.
Source Firkin
A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.
Source Firkin
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
A seamless pattern formed from a tile that can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Remixed from a raster on Pixabay that was uploaded by ArtsyBee.
Source Firkin
The act or state of corrugating or of being corrugated, a wrinkle; fold; furrow; ridge.
Source Anna Litvinuk
The act or state of corrugating or of being corrugated, a wrinkle; fold; furrow; ridge.
Source Anna Litvinuk
If you like it a bit trippy, this wave pattern might be for you.
Source Ian Soper
Dark blue concrete wall with some small dust spots.
Source Atle Mo
Fake or not, it’s quite luxurious.
Source Factorio.us Collective
Sounds French. Some 3D square diagonals, that’s all you need to know.
Source Graphiste
Prismatic Groovy Concentric Background 2
Source GDJ
The name tells you it has curves. Oh yes, it does!
Source Peter Chon