Based on an image that was uploaded to Pixabay by devanath
Source Firkin
A seamless background pattern with impressed gray dots.
Source V. Hartikainen
A bit of scratched up grayness. Always good.
Source Dmitry
Lovely pattern with some good-looking non-random noise lines.
Source Zucx
The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
This is a seamless pattern of regular hexagon which has a honeycomb structure.
Source Yamachem
Light gray grunge wall with a nice texture overlay.
Source Adam Anlauf
Small gradient crosses inside 45-degree boxes, or bigger crosses if you will.
Source Wassim
Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Prismatic Curved Diamond Pattern 6 No Background
Source GDJ
Zero CC tillable hard cover red book with X shape marks. Scanned and made by me.
Source Sojan Janso
A dark metallic background with a pattern of stamped dots. Here's a dark "metallic" background pattern for you.
Source V. Hartikainen
This one takes you back to math class. Classic mathematic board underlay.
Source Josh Green
One more from Badhon, sharp horizontal lines making an embossed paper feeling.
Source Badhon Ebrahim
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
A seamless pattern based on a square tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
A seamless pattern with wide vertical stripes colored in pale yellow.
Source V. Hartikainen