The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Black version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
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
An abstract texture of black metal pipes (seamless).
Source V. Hartikainen
From a drawing in 'Cowdray: the history of a great English House', Julia Roundell, 1884.
Source Firkin
A seamless background texture of old cardboard.
Source V. Hartikainen
Scanned some rice paper and tiled it up for you. Enjoy.
Source Atle Mo
A free grid paper background pattern for using on web sites.
Source V. Hartikainen
Seamless Prismatic Pythagorean Line Art Pattern No Background. A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).
Source GDJ
Zero CC tileable hard cover green book, scanned and made by me. CC0
Source Sojan Janso
A chequerboard pattern with a fruit theme. The fruits are from a posting by inkscapeforum.it.
Source Firkin
Not so subtle. These tileable wood patterns are very useful.
Source Elemis
The edges of all the red objects line up either vertically or horizontally, but it doesn't appear so. Made from a square tile that can be got by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
This seamless pattern consists of a blue grid on a yellow background.
Source V. Hartikainen
The tile can be had by selecting the rectangle in Inkscape and using shift+alt+i. Remixed from a drawing in 'Flowers of Song', Frederick Weatherly, 1895.
Source Firkin
Lovely light gray floral motif with some subtle shades.
Source GraphicsWall
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
From a drawing in 'Uit de geschiedenis der Heilige Stede te Amsterdam', Yohannes Sterck, 1898.
Source Firkin
Small gradient crosses inside 45-degree boxes, or bigger crosses if you will.
Source Wassim
Prismatic Hypnotic Pattern 2 No Background
Source GDJ
Dark blue concrete wall with some small dust spots.
Source Atle Mo
Colour version that is close to the original drawing uploaded to Pixabay by pencilparker.
Source Firkin