Looks a bit like concrete with subtle specks spread around the pattern.
Source Mladjan Antic
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
Inspired by a pattern found in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
This one is amazing, truly original. Go use it!
Source Viahorizon
A seamless background of warped stripes on paper.
Source V. Hartikainen
Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
Prismatic Polka Dots Mark II 2 No Background
Source GDJ
Same as Silver Scales, but in black. Turn your site into a dragon with this great scale pattern.
Source Alex Parker
The tile this is based on can be retrieved by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Zero CC tileable hard cover green book, scanned and made by me. CC0
Source Sojan Janso
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
This is the remix of "blue wave-seigaiha".The image depicts a seamless pattern of the front upper part of Japanese five yen coin which is used currently.This design represents a rice with ripe golden ears.
Source Yamachem
A seamless texture of worn out "cardboard".
Source V. Hartikainen
A very dark spotted twinkle pattern for your twinkle needs.
Source Badhon Ebrahim
Lovely pattern with splattered vintage speckles.
Source David Pomfret
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Zero CC tileable dry grass texture, photographed and made by me. CC0
Source Sojan Janso
Orange-red pattern for tiled backgrounds.
Source V. Hartikainen