Zero CC tileable seed texture, edited by me to be seamless from a Pixabay image. CC0
Source Sojan Janso
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A seamless pattern the starting point for which was a 'rainbow twist' texture in Paint.net.
Source Firkin
Light gray version of the Binding pattern that looks a bit like fabric.
Source Newbury
It looks like a polished stone surface to me. Download it for free, as always.
Source V. Hartikainen
Prismatic Abstract Geometric Background derived from an image on Pixabay.
Source GDJ
Paper pattern with small dust particles and 45-degree strokes.
Source Atle Mo
Adapted from an image that was uploaded to Pixabay by Anerma.
Source Firkin
Lovely pattern with some good-looking non-random noise lines.
Source Zucx
Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Background Wall, Art Abstract, Blue Well & CC0 texture.
Source Ractapopulous
A free seamless background texture that looks like a brown stone wall.
Source V. Hartikainen
Like the name says, light and gray, with some small dots and circles.
Source Brenda Lay
This seamless background image should look nice on websites. It has a dark blue gray texture with vertical stripes, it tiles seamlessly and, like all of the background images here, it's free. So, if you like it, take it!
Source V. Hartikainen
Little x’es, noise and all the stuff you like. Dark like a Monday, with a hint of blue.
Source Tom McArdle
Prismatic Curved Diamond Pattern 3 No Background
Source GDJ
This is the third pattern called Dark Denim, but hey, we all love them!
Source Brandon Jacoby
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
The image is the remix of "wire-mesh fence seamless pattern" .This is a more minute version of it.Sorry for the file size.Using path>difference in Inkscape, I will cut out any silhouette from this pattern and create a "meshed silhouette".
Source Yamachem
This is the remix of an Openclipart clipart called "Maze" uploaded by "any_ono_mous".Thanks.This is a seamless pattern of a maze.
Source Yamachem