A simple example on using clones. You can generate a nice base for a pattern fill quickly with it.
Source Lazur URH
This tiled background comes in red and consists of tiles that look like gemstones. It is more for blogs or social profiles, I think.
Source V. Hartikainen
Lovely pattern with some good-looking non-random noise lines.
Source Zucx
Remixed from a drawing in 'The Canadian horticulturist', 1892
Source Firkin
The image depicts a seamless pattern of a Japanese family crest called "chidori" in Japanese .A chidori in Japanese means a plover in English.
Source Yamachem
Remixed from a raster on Pixabay that was uploaded by ArtsyBee.
Source Firkin
A seamless design of flowers remixed from a jpg on Pixabay by Prawny.
Source Firkin
Retro Circles Background 7 No Black
Source GDJ
Prismatic Abstract Background Design
Source GDJ
A bit like smudged paint or some sort of steel, here is scribble light.
Source Tegan Male
More bright luxury. This is a bit larger than fancy deboss, and with a bit more noise.
Source Viszt Péter
Number 3 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Prismatic Polka Dots Mark II 2 No Background
Source GDJ
Formed from a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Remixed from a drawing that was uploaded to Pixabay by DavidZydd
Source Firkin
Prismatic Groovy Concentric Background 3 No Black
Source GDJ
A seamless pattern created from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Prismatic Abstract Geometric Background 2
Source GDJ
A seamless pattern drawn originally in Paint.net by distorting a slice of background pattern 116 and copying the resulting triangle numerous times.
Source Firkin
A seamless pattern formed from miutopia's cakes on a tablecloth.
Source Firkin
Prismatic Triangular Background Design Mark II 5
Source GDJ
Super simple but very nice indeed. Gray with vertical stripes.
Source Merrin Macleod
The tile this is formed from can be retrieved in Inkscape by selecting the rectangle and using shift+alt+i
Source Firkin
This is the remix of "blue wave-seigaiha".This is the flowers of pink silk tree which is called "nemuno-ki".About pink silk tree ,refer to here:https://jp.pinterest.com/pin/500744052301210439/
Source Yamachem
A version without colours blended together to give a different look.
Source Firkin
From a design in 'Storia del Palazzo Vecchio in Firenze', Aurelio Gotti, 1889.
Source Firkin
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua