A simple example on using clones. You can generate a nice base for a pattern fill quickly with it.
Source Lazur URH
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
If you’re sick of the fancy 3D, grunge and noisy patterns, take a look at this flat 2D brick wall.
Source Listvetra
Prismatic Isometric Cube Extra Pattern No Background
Source GDJ
Zero CC tileable seed texture, edited by me to be seamless from a Pixabay image. CC0
Source Sojan Janso
Like the name suggests, this background image consists of a pattern of dark bricks. It may be an option for you, if you are looking for something that looks like a brick wall for use as a background on web pages. It's not a masterpiece, but looks pretty nice when is tiled.
Source V. Hartikainen
A dark brown fabric-like background texture with seamless pattern of winding stripes.
Source V. Hartikainen
A pattern derived from repeating unit cells each derived from part of a fractal rendering in paint.net.
Source Firkin
Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Just what the name says, paper fibers. Always good to have.
Source Heliodor jalba
No, not the band but the pattern. Simple squares in gray tones, of course.
Source Atle Mo
From a drawing in 'Cowdray: the history of a great English House', Julia Roundell, 1884.
Source Firkin
Sort of like the Photoshop transparent background, but better!
Source Alex Parker
I know there is one here already, but this is sexy!
Source Gjermund Gustavsen
This one is super crisp at 2X. Lined paper with some dust and scratches.
Source HQvectors
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
To get the tile this is based on, select the rectangle in Inkscape and use 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
Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Sounds like something from World of Warcraft. Has to be good.
Source Tony Kinard