As far as fabric patterns goes, this is quite crisp.
Source Heliodor Jalba
Abstract Tiled Background Extended 8
Source GDJ
From a drawing in 'Hyde Park from Domesday-Book to date', John Ashton, 1896.
Source Firkin
Formed by distorting a JPG from PublicDomainPictures
Source Firkin
A seamless pattern the starting point for which was a 'light rays' rendering in Paint.net.
Source Firkin
The name alone is awesome, but so is this sweet dark pattern.
Source Federica Pelzel
This is a hot one. Small, sharp and unique.
Source GraphicsWall
A seamless web texture of "green stone".
Source V. Hartikainen
Dark, square, clean and tidy. What more can you ask for?
Source Jaromír Kavan
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
Real snow that tiles, not easy. This is not perfect, but an attempt.
Source Atle Mo
You know I’m a sucker for these. Well-crafted paper pattern.
Source Mihaela Hinayon
Did anyone say The Hoff? This pattern is in no way related to Baywatch.
Source Josh Green
Prismatic Rounded Squares Grid 4 No Background
Source GDJ
Abstract Tiled Background Extended 10
Source GDJ
Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
This background pattern looks like bamboo to me. Feel free to download it for your website (for your blog perhaps?).
Source V. Hartikainen
A browner version of the original weathered fence texture.
Source Firkin
Pattern that came out of playing with the 'slinky' plug-in for Paint.net
Source Firkin
One more in the line of patterns inspired by Japanese/Asian styles. Smooth.
Source Kim Ruddock
Prismatic Abstract Geometric Background 5 No Black
Source GDJ
Thin lines, noise and texture creates this crisp dark denim pattern.
Source Marco Slooten
Dark wooden pattern, given the subtle treatment. based on texture from Cloaks.
A repeating background for websites with a texture of black groove stripes.
Source V. Hartikainen
Adapted from an image that was uploaded to Pixabay by Anerma.
Source Firkin
Remixed from a drawing in 'Paul's Sister', Frances Peard, 1889.
Source Firkin