Produced using the clouds, flames and glass blocks plug-ins in Paint.net and the resulting .PNG vectorised with Vector Magic.
Source Firkin
A seamless textured paper for backgrounds. Colored in pale orange hues.
Source V. Hartikainen
ZeroCC tileable stone texture, edited from pixabay, CC0
Source Sojan Janso
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
From a design found in 'History of the Virginia Company of London; with letters to and from the first Colony, never before printed', Edward Neill, 1869.
Source Firkin
Dare I call this a «flat pattern»? Probably not.
Source Dax Kieran
Beautiful dark noise pattern with some dust and grunge.
Source Vincent Klaiber
Wasn't satisfied with the original's colouring. Too much component transfer and colormatrixes yet the results are lacking a bit. So this time it is a simple black to transparent fade, making it possible remixing easily once there will be other blending modes supported as well. Probably in inkscape 0.92.
Source Lazur URH
The tile this fill pattern is based on can be had by using shift+alt+i on the rectangle.
Source Firkin
A background pattern with blue on white vertical stripes.
Source V. Hartikainen
A web texture of brown canvas. Will look great, when used in dark web designs.
Source V. Hartikainen
Almost like little fish shells, or dragon skin.
Source Graphiste
Luxurious looking pattern (for a T-shirt maybe?) with a hint of green.
Source Simon Meek
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
From a drawing in 'Navigations de Alouys de Cademoste.-La Navigation du Capitaine Pierre Sintre', Alvise da ca da Mosto, 1895.
Source Firkin
This reminds me of Game Cube. A nice light 3D cube pattern.
Source Sander Ottens
Derived from a corner decoration itself found as a jpg on Pixabay.
Source Firkin
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin