To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A simple example on using clones. You can generate a nice base for a pattern fill quickly with it.
Source Lazur URH
Background Wall, Art Abstract, Block Well & CC0 texture.
Source Ractapopulous
This ons is quite old school looking. Retro, even. I like it.
Source Arno Declercq
CC0 and seamless wellington boot pattern.
Source SliverKnight
Scanned some rice paper and tiled it up for you. Enjoy.
Source Atle Mo
From a drawing in 'Worsborough; its historical associations and rural attractions', Joseph Wilkinson, 1879.
Source Firkin
From a drawing of the coat of arms of the Ottoman Empire on Wikimedia.
Source Firkin
Same as the black version, but now in shades of gray. Very subtle and fine grained.
Source Atle Mo
Number 1 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
Remixed from a vector adapted from a jpg on Pixabay. The tile this is constructed from can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Prismatic Geometric Pattern Background 2 No Black
Source GDJ
Bright Multicolored Floral Background by Karen Arnold from PDP.
Source GDJ
Prismatic Geometric Pattern Background 2
Source GDJ
Zero CC tileable cork floor, photographed and made by me. CC0
Source Sojan Janso
A repeating background with seamless texture of stone. There haven't been any stone-like backgrounds for a while, so I have decided to create one more. The rest can be found in the appropriate category.
Source V. Hartikainen
Dark blue concrete wall with some small dust spots.
Source Atle Mo
Seamless pattern formed from a square tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
This one could be the shirt of a golf player. Angled lines in different thicknesses.
Source Olivier Pineda
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Simple gray checkered lines, in light tones.
Source Radosław Rzepecki
Inspired by a pattern found in 'A General History of Hampshire, or the County of Southampton, including the Isle of Wight', Bernard Woodwood, 1861
Source Firkin
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Background Wall, Art Abstract, Blue Well & CC0 texture.
Source Ractapopulous
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight