Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
A seamless tessellation pattern. To get the tile this is formed from, select the pattern in Inkscape and use shift+alt+i.
Source Firkin
Dark Tile-able Grunge Texture. I think this texture can be classified as grunge. It's free and seamless, as always.
Source V. Hartikainen
Seamless Prismatic Geometric Pattern With Background
Source GDJ
Love me some light mesh on a Monday. Sharp.
Source Wilmotte Bastien
A light gray background pattern with seamless fabric-like texture and almost unnoticeable stripes.
Source V. Hartikainen
Lovely pattern with some good-looking non-random noise lines.
Source Zucx
Sharp pixel pattern, just like the good old days.
Source Paridhi
Crossing lines with a subtle emboss effect on a dark background.
Source Stefan Aleksić
Prismatic Abstract Geometric Background 5 No Black
Source GDJ
Sweet and subtle white plaster with hints of noise and grunge.
Source Phil Maurer
Sort of like the back of a wooden board. Light, subtle, and stylish, just the way we like it!
Source Nikolalek
Lovely pattern with splattered vintage speckles.
Source David Pomfret
The tile for this is based on a repeating unit close to a design on Pixabay. It can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Like the name suggests, this background image consists of a pattern of dark bricks. It may be an option for you, if you are looking for something that looks like a brick wall for use as a background on web pages. It's not a masterpiece, but looks pretty nice when is tiled.
Source V. Hartikainen
A background pattern with a look of rough fabric.
Source V. Hartikainen
Small gradient crosses inside 45-degree boxes, or bigger crosses if you will.
Source Wassim
A simple circle. That’s all it takes. This one is even transparent, for those who like that.
Source Saqib
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
I have no idea what J Boo means by this name, but hey – it’s hot.
Source j Boo
You know I love paper patterns. Here is one from Stephen. Say thank you!
Source Stephen Gilbert