Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
Dark blue concrete wall with some small dust spots.
Source Atle Mo
A dark metallic background with a pattern of stamped dots. Here's a dark "metallic" background pattern for you.
Source V. Hartikainen
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
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
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
From a drawing in 'Navigations de Alouys de Cademoste.-La Navigation du Capitaine Pierre Sintre', Alvise da ca da Mosto, 1895.
Source Firkin
Prismatic Groovy Concentric Background 3
Source GDJ
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Basket Fibers, Basket Texture, Braid Background style CC0 texture.
Source 1A-Photoshop
This one is super crisp at 2X. Lined paper with some dust and scratches.
Source HQvectors
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
Prismatic Geometric Tessellation Pattern No Background
Source GDJ
A comeback for you: the popular Escheresque, now in black.
Source Patten
Black paper texture, based on two different images.
Source Atle Mo
Based from Design Kindle
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A series of 5 patterns. That’s what the P stands for, if you didn’t guess it.
Source Dima Shiper
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
A light brushed aluminum pattern for your pleasure.
Source Tim Ward
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Here I have tried to create something that would look like maple wood. Not sure how well it's turned out, but at least it looks like wood.
Source V. Hartikainen
A seamless pattern with wide vertical stripes colored in pale yellow.
Source V. Hartikainen
One more sharp little tile for you. Subtle circles this time.
Source Blunia
A seamless pattern drawn originally in Paint.net by distorting a slice of background pattern 116 and copying the resulting triangle numerous times.
Source Firkin
Just like your old suit, all striped and smooth.
Source Alex Berkowitz
This reminds me of Game Cube. A nice light 3D cube pattern.
Source Sander Ottens