You can never get enough of these tiny pixel patterns with sharp lines.
Source Designova
Greyscale version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
Abstract Ellipses Background Grayscale
Source GDJ
High detail stone wall with minor cracks and specks.
Source Projecteightyfive
This is a remix of "flower seamless pattern".I rotated the original image by 90 degrees.This is a seamless pattern of flowers.These horizontal wavy lines are one of Edo patterns which is called "tatewaku or tachiwaku or 立湧" that represents uprising steam or vapor.
Source Yamachem
Prismatic Geometric Tessellation Pattern 4 No Background
Source GDJ
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Same classic 45-degree pattern, dark version.
Source Luke McDonald
This seamless pattern consists of a blue grid on a yellow background.
Source V. Hartikainen
One more from Badhon, sharp horizontal lines making an embossed paper feeling.
Source Badhon Ebrahim
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A pale yellow background pattern with vertical stripes. The stripes are partially faded. I think this background image turned out pretty well, especially those faded stripes.
Source V. Hartikainen
A good starting point for a cardboard pattern. This would work well in a variety of colors.
Source Atle Mo
Lovely pattern with some good-looking non-random noise lines.
Source Zucx
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
I took the liberty of using Dmitry’s pattern and made a version without perforation.
Source Atle Mo
Scanned some rice paper and tiled it up for you. Enjoy.
Source Atle Mo
Pattern formed from simple shapes. Black version.
Source Firkin
From a drawing in 'Kingsdene', Maria Fetherstonehaugh, 1878.
Source Firkin
Not so subtle. These tileable wood patterns are very useful.
Source Elemis