As far as fabric patterns goes, this is quite crisp.
Source Heliodor Jalba
A free background pattern with abstract green tiles.
Source V. Hartikainen
From a drawing in 'Picturesque New Guinea', J Lindt, 1887.
Source Firkin
This is a semi-dark pattern, sort of linen-y.
Source Sagive SEO
Seamless tile drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
Everyone loves a diamond, right? Make your site sparkle.
Source AJ Troxell
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
This was submitted in a beige color, hence the name. Now it’s a gray paper pattern.
Source Konstantin Ivanov
This ladies and gentlemen, is texturetastic! Love it.
Source Adam Pickering
The Grid. A digital frontier. I tried to picture clusters of information as they traveled through the computer.
Source Haris Šumić
Your eyes can trip a bit from looking at this – use it wisely.
Source Michal Chovanec
A mid-tone gray pattern with some cement looking texture.
Source Hendrik Lammers
Remixed from a drawing in 'Line and form", Walter Crane, 1914.
Source Firkin
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
As far as fabric patterns goes, this is quite crisp.
Source Heliodor Jalba
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
This was formed by distorting an image of a background on Pixabay.
Source Firkin
This reminds me of Game Cube. A nice light 3D cube pattern.
Source Sander Ottens
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Everyone needs some stardust. Sprinkle it on your next project.
Source Atle Mo