CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Number 3 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
Derived from an image that was uploaded to Pixabay by darkmoon1968
Source Firkin
More tactile goodness. This time in the form of some rough cloth.
Source Bartosz Kaszubowski
A seamless pattern with a unit cell drawn as a bitmap in Paint.net and vectorized in Vector Magic.
Source Firkin
You could get a bit dizzy from this one, but it might come in handy.
Source Dertig Media
This was formed by distorting an image of a background on Pixabay.
Source Firkin
I know there is one here already, but this is sexy!
Source Gjermund Gustavsen
Washi (和紙?) is a type of paper made in Japan. Here’s the pattern for you!
Source Carolynne
A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
From a design found in 'History of the Virginia Company of London; with letters to and from the first Colony, never before printed', Edward Neill, 1869.
Source Firkin
Drawn in Paint.net and vectorised in Vector Magic.
Source Firkin
A seamless dark leather-like background texture with diagonal lines that look like stitches.
Source V. Hartikainen
This metal background pattern resembles a metal plate with rivets. Solid rivets on a metal plate.
Source V. Hartikainen
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
There are quite a few grid patterns, but this one is a super tiny grid with some dust for good measure.
Source Dominik Kiss
Tiny little fibers making a soft and sweet look.
Source Badhon Ebrahim
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A new one called white wall, not by me this time.
Source Yuji Honzawa
Pattern that came out of playing with the 'slinky' plug-in for Paint.net
Source Firkin
Colorful Floral Background 3 No Black
Source GDJ
You can never get enough of these tiny pixel patterns with sharp lines.
Source Designova
Prismatic Abstract Geometric Background 4 No Black
Source GDJ