The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
A repeating background for websites with a texture of black groove stripes.
Source V. Hartikainen
A free pink background pattern.
Source V. Hartikainen
Everyone needs some stardust. Sprinkle it on your next project.
Source Atle Mo
This is so subtle I hope you can see it! Tweak at will.
Source Alexandre Naud
Number 3 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
I know there is one here already, but this is sexy!
Source Gjermund Gustavsen
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
ZeroCC tileable beechwood wood texture, generated in Neo Texture Edit by me. CC0
Source Sojan Janso
And some more testing, this time with Seamless Studio. It’s Robots FFS!
Source Seamless Studio
Little x’es, noise and all the stuff you like. Dark like a Monday, with a hint of blue.
Source Tom McArdle
The image depicts a tiled seamless pattern.The tile represents four leaves aligned every 90 ° , which may look like a bird or a dragon .The original leaf design is from a Japanese old book.
Source Yamachem
Prepared mostly as a raster in Paint.net and vectorised.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Semi-light fabric pattern made out of random pixels in shades of gray.
Source Atle Mo
Light and tiny, just the way you like it.
Source Rohit Arun Rao
Remixed from a design on Pixabay. To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Zero CC tileable hard cover green book, scanned and made by me. CC0
Source Sojan Janso
Abstract Arbitrary Geometric Background derived from an image on Pixabay.
Source GDJ
Beautiful dark noise pattern with some dust and grunge.
Source Vincent Klaiber
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
From a drawing in 'Heroes of North African Discovery', Nancy Meugens, 1894.
Source Firkin
Prismatic Hypnotic Pattern 2 No Background
Source GDJ
The classic subtle pattern. Sort of wall/brick looking. Or moon-looking?
Source Joel Klein
The Grid. A digital frontier. I tried to picture clusters of information as they traveled through the computer.
Source Haris Šumić