Classic 45-degree pattern, light version.
Source Luke McDonald
This one is super crisp at 2X. Lined paper with some dust and scratches.
Source HQvectors
Dark Tile-able Grunge Texture. I think this texture can be classified as grunge. It's free and seamless, as always.
Source V. Hartikainen
f you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
Drawn in Paint.net using the kaleidoscope plug-in and vectorised.
Source Firkin
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
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
A bit strange this one, but nice at the same time.
Source Diogo Silva
Sometimes you just need the simplest thing.
Source Fabricio
Luxurious looking pattern (for a T-shirt maybe?) with a hint of green.
Source Simon Meek
All good things come in threes, so I give you the third in my little concrete wall series.
Source Atle Mo
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Semi-light fabric pattern made out of random pixels in shades of gray.
Source Atle Mo
A seamless pattern of leopard skin. It should look nice as a background element on web pages.
Source V. Hartikainen
Semi-light fabric pattern made out of random pixels in shades of gray.
Source Atle Mo
White fabric looking texture with some nice random wave features.
Source Hendrik Lammers
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
More Japanese-inspired patterns, Gold Scales this time.
Source Josh Green
A light brushed aluminum pattern for your pleasure.
Source Tim Ward
Not a flat you live inside, like in the UK – but a flat piece of cardboard.
Source Appleshadow