Sounds French. Some 3D square diagonals, that’s all you need to know.
Source Graphiste
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
Not so subtle. These tileable wood patterns are very useful.
Source Elemis
Zero CC tileable Laminate wood texture, photographed and made by me. CC0
Source Sojan Janso
Green Background Pattern
Source V. Hartikainen
Like the name says, light and gray, with some small dots and circles.
Source Brenda Lay
First pattern tailor-made for Retina, with many more to come. All the old ones are upscaled, in case you want to re-download.
Source Atle Mo
Coming in at 666x666px, this is an evil big pattern, but nice and soft at the same time.
Source Atle Mo
Remixed from a design on Pixabay. To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
This is lovely, just the right amount of subtle noise, lines and textures.
Source Richard Tabor
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Inspired by the B&O Play, I had to make this pattern.
Source Atle Mo
Prismatic Curved Diamond Pattern 7 No Background
Source GDJ
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
The name Paisley reminds me of an old British servant. That’s just me.
Source Swetha
Here's a subtle marble-like background for use on websites.
Source V. Hartikainen
Super subtle indeed, a medium gray pattern with tiny dots in a grid.
Source Designova
Fabric-ish patterns are close to my heart. French Stucco to the rescue.
Source Christopher Buecheler
A repeating background with seamless texture of stone. There haven't been any stone-like backgrounds for a while, so I have decided to create one more. The rest can be found in the appropriate category.
Source V. Hartikainen
Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin