Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
It was called Navy Blue, but I made it dark. You know, the way I like it.
Source Ethan Hamilton
Zero CC tileable pine bark texture, photographed and made by me. CC0
Source Sojan Janso
Sharp diamond pattern. A small 24x18px tile.
Source Tom Neal
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
Prismatic Groovy Concentric Background 3 No Black
Source GDJ
A seamless pattern from a tile made from a jpg on Pixabay. To get the tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
The following repeating website background is colored in a blue gray color and resembles a concrete wall or something similar to it.
Source V. Hartikainen
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin
This seamless pattern consists of a blue grid on a yellow background.
Source V. Hartikainen
A seamless background tile of aged paper with shabby look.
Source V. Hartikainen
From a drawing in 'A Rolling Stone. A tale of wrongs and revenge', John Hartley, 1878.
Source Firkin
The image is a remix of "edo pattern-samekomon".I changed the color of dots from black to white and added BG in light-yellow.
Source Yamachem
One more sharp little tile for you. Subtle circles this time.
Source Blunia
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
A rusty grunge background for websites. Feel free to use it in your site's theme.
Source V. Hartikainen
Tweed is back in style – you heard it here first. Also, the @2X version here is great!
Source Simon Leo
The tile this is based on can be retrieved by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin