From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
Prismatic Isometric Cube Extra Pattern No Background
Source GDJ
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
This makes me wanna shoot some pool! Sweet green pool table pattern.
Source Caveman
This pack of filters can help you adding a blocky overlay to objects. May come handy at drawing blocks of stone.
Source Lazur URH
Not so subtle. These tileable wood patterns are very useful.
Source Elemis
The tile this fill pattern is based on can be had by using shift+alt+i on the rectangle.
Source Firkin
Looks like a technical drawing board: small squares forming a nice grid.
Source We Are Pixel8
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Background pattern originally a PNG drawn in Paint.net
Source Firkin
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
This is a hot one. Small, sharp and unique.
Source GraphicsWall
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
Derived from an image that was uploaded to Pixabay by darkmoon1968
Source Firkin
A rusty grunge background for websites. Feel free to use it in your site's theme.
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
Derived from a drawing in 'The Murmur of the Shells', Samuel Cowen, 1879.
Source Firkin
If you don’t like cream and pixels, you’re in the wrong place.
Source Mizanur Rahman
Prismatic Floral Background No Black
Source GDJ
Based on an image that was uploaded to Pixabay by devanath
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A dark background pattern/texture of a dimpled metal plate.
Source V. Hartikainen
It looks very nice I think.
Source V. Hartikainen
Seamless Olive Green Web Background Image
Source V. Hartikainen