A smooth mid-tone gray, or low contrast if you will, linen pattern.
Source Jordan Pittman
Derived from an image that was uploaded to Pixabay by Kaz
Source Firkin
Looks a bit like concrete with subtle specks spread around the pattern.
Source Mladjan Antic
Prismatic Groovy Concentric Background No Black
Source GDJ
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Just like the black maze, only in light gray. Duh.
Source Peax
I have no idea what J Boo means by this name, but hey – it’s hot.
Source j Boo
Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
A pattern formed from a squared tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Pixel by pixel, sharp and clean. Very light pattern with clear lines.
Source M.Ashok
Derived from a drawing in 'Elfrica. An historical romance of the twelfth century', Charlotte Boger, 1885
Source Firkin
Formed by distorting a JPG from PublicDomainPictures
Source Firkin
Prismatic Curved Diamond Pattern 5 No Background
Source GDJ
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
More tactile goodness. This time in the form of some rough cloth.
Source Bartosz Kaszubowski
White little knobs, coming in at 10x10px. Sweet!
Source Amos
Bit of a strange name on this one, but still nice. Tiny gray square things.
Source Carlos Valdez
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
Alternative colour scheme for the original floral pattern.
Source Firkin