This is so subtle you need to bring your magnifier!
Source Carlos Valdez
From a drawing in 'Az Osztrák-Magyar Monarchia irásban és képben', 1885.
Source Firkin
Derived from an image that was uploaded to Pixabay by Darkmoon1968
Source Firkin
Snap! It’s a pattern, and it’s not grayscale! Of course you can always change the color in Photoshop.
Source Atle Mo
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
This one is super crisp at 2X. Lined paper with some dust and scratches.
Source HQvectors
This is a seamless pattern of regular hexagon which has a honeycomb structure.
Source Yamachem
Colorful Floral Background 3 No Black
Source GDJ
Utilising a bird from s-light and some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Pattern formed from simple shapes. Black version.
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A seamless pattern based on a square tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
A seamless background drawn in Paint.net and vectorised with Vector Magic. The starting point was a photograph of drinking straws from Pixabay.
Source Firkin
A mid-tone gray pattern with some cement looking texture.
Source Hendrik Lammers
A pattern derived from repeating unit cells each derived from part of a mosaic in paint.net. The starting point for the mosaic was a picture of some prawns!
Source Firkin
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
A very dark spotted twinkle pattern for your twinkle needs.
Source Badhon Ebrahim
Same as the black version, but now in shades of gray. Very subtle and fine grained.
Source Atle Mo
A seamless pattern with wide vertical stripes colored in pale yellow.
Source V. Hartikainen
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A seamless paper background colored in pale yellow.
Source V. Hartikainen
A simple example on using clones. You can generate a nice base for a pattern fill quickly with it.
Source Lazur URH