Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
Got some felt in my mailbox today, so I scanned it for you to use.
Source Atle Mo
Number 1 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Nice and simple crossed lines in dark gray tones.
Source Stefan Aleksić
Inspired by a pattern seen on a public domain image of a very old tile. To get the unit cell, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
To get the tile this is made up from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Like the name says, light and gray, with some small dots and circles.
Source Brenda Lay
High detail stone wall with minor cracks and specks.
Source Projecteightyfive
Just a nice looking textured pattern with faded blue stripes. Well, that's it for today... one background a day, as usual.
Source V. Hartikainen
Not sure if this is related to the Nami you get in Google image search, but hey, it’s nice!
Source Dertig Media
From a drawing in 'Studies for Stories', Jean Ingelow, 1864.
Source Firkin
A dark background pattern/texture of a dimpled metal plate.
Source V. Hartikainen
I’m starting to think I have a concrete wall fetish.
Source Atle Mo
This was formed by distorting an image of a background on Pixabay.
Source Firkin
A white version of the very popular linen pattern.
Source Ant Ekşiler
Zero CC tileable bark texture, photographed and made by me. CC0
Source Sojan Janso
It has waves, so make sure you don’t get sea sickness.
Source CoolPatterns
Prismatic Polka Dots Mark II 3 No Background
Source GDJ
A free seamless background texture of "timber wall" (colored in dark brown).
Source V. Hartikainen