A simple example on using clones. You can generate a nice base for a pattern fill quickly with it.
Source Lazur URH
I took the liberty of using Dmitry’s pattern and made a version without perforation.
Source Atle Mo
CC0 remixed from a drawing. Walter Crane, 1914, Firkin.
Source SliverKnight
From a drawing in 'Real Sailor-Songs', John Ashton, 1891.
Source Firkin
It was called Navy Blue, but I made it dark. You know, the way I like it.
Source Ethan Hamilton
A seamless pattern created from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
From an image on opengameart.org shared by rubberduck.
Source Firkin
The image is a seamless pattern of a fishnet.
Source Yamachem
The image a seamless pattern derived from a weed which I can't identify.The original weed image is from here:https://jp.pinterest.com/pin/500744052301423641/
Source Yamachem
Pattern produced in Paint.net using the Vibrato plug-in.
Source Firkin
Just like the black maze, only in light gray. Duh.
Source Peax
A seamless pattern formed from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Same as the black version, but now in shades of gray. Very subtle and fine grained.
Source Atle Mo
An abstract web texture of a polished blue stone (or does it look more like ice).
Source V. Hartikainen
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
This was formed by distorting an image of a background on Pixabay.
Source Firkin
Prismatic Abstract Background Design
Source GDJ
Bit of a strange name on this one, but still nice. Tiny gray square things.
Source Carlos Valdez
Could be paper, could be a Polaroid frame – up to you!
Source Chaos
Detailed but still subtle and quite original. Lovely gray shades.
Source Kim Ruddock
The act or state of corrugating or of being corrugated, a wrinkle; fold; furrow; ridge.
Source Anna Litvinuk
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin