A simple example on using clones. You can generate a nice base for a pattern fill quickly with it.
Source Lazur URH
This one is rather fun and playful. The 2X could be used at 1X too!
Source Welsley
Fix and cc0 to get the tile this is based on.
Source SliverKnight
More Japanese-inspired patterns, Gold Scales this time.
Source Josh Green
ZeroCC tileable stone texture, edited from pixabay, CC0
Source Sojan Janso
Zero CC tileable seed texture, edited by me to be seamless from a Pixabay image. CC0
Source Sojan Janso
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A subtle shadowed checkered pattern. Increase the lightness for even more subtle sexiness.
Source Josh Green
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Colorful Floral Background No Black
Source GDJ
Here's a seamless brown cork board background texture. Feel free to download or reshare if you like.
Source V. Hartikainen
Zero CC tileable yellow craft paper; scanned and made by me. CC0
Source Sojan Janso
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
To celebrate the new feature, we need some sparkling diamonds.
Source Atle Mo
Prismatic Geometric Pattern Background
Source GDJ
Don’t look at this one too long if you’re high on something.
Source Luuk van Baars
Same as Silver Scales, but in black. Turn your site into a dragon with this great scale pattern.
Source Alex Parker
A seamless pattern formed from a square tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Abstract Tiled Background Extended 10
Source GDJ
Small dots with minor circles spread across to form a nice mosaic.
Source John Burks
Background formed from the iconic plastic construction bricks that gave me endless hours of fun when I was a lad.
Source Firkin