This one is so simple, yet so good. And you know it. Has to be in the collection.
Source Gluszczenko
Seamless Prismatic Pythagorean Line Art Pattern No Background. A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).
Source GDJ
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
A very dark spotted twinkle pattern for your twinkle needs.
Source Badhon Ebrahim
The image depicts meshed silhouettes of various things.The original image is an OCAL clipart called "Enter FOSSASIA 2016 #IoT T-shirt Design Contest" uploaded by "openclipart".Thanks.
Source Yamachem
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
A seamless background colored in pale orange. It has a paper like texture with diagonal grid pattern.
Source V. Hartikainen
Seamless SVG vector and JPG backgrounds with faded diagonal stripes. The colors are editable.
Source V. Hartikainen
Detailed but still subtle and quite original. Lovely gray shades.
Source Kim Ruddock
An abstract texture of water. It's not perfect, but will do. You may download if you like it.
Source V. Hartikainen
I love cream! 50x50px and lovely in all the good ways.
Source Thomas Myrman
From a drawing in 'Codogno e il suo territorio nella cronaca e nella storia'', Gio and Giarella Cairo, 1897.
Source Firkin
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
A pattern formed from a photograph of a 16th century ceramic tile.
Source Firkin
Vertical lines with a bumpy, yet crisp, feel to it.
Source Raasa
This ons is quite old school looking. Retro, even. I like it.
Source Arno Declercq
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Zero CC plastic pattern texture, photographed and made by me. CC0 *Note, this texture was on the perfectly smooth surface of a plastic shovel scraper, not sure how to call it. Plz coment if you know what its called.
Source Sojan Janso
This is a semi-dark pattern, sort of linen-y.
Source Sagive SEO
The tile this fill pattern is based on can be had by using shift+alt+i on the rectangle.
Source Firkin