A nice one indeed, but I have a feeling we have it already? If you spot a copy, let me know on Twitter.
Source Graphiste
A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).
Source GDJ
Alternative colour scheme. Not a pattern for fabrics, but one produced from a jpg of a stack of fabric items that was posted on Pixabay. The tile that this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
This is a semi-dark pattern, sort of linen-y.
Source Sagive SEO
A seamless pattern of dark bricks. Maybe it's not very realistic, but it looks good in my opinion.
Source V. Hartikainen
Number 2 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A seamless paper background colored in pale yellow.
Source V. Hartikainen
Simple gray checkered lines, in light tones.
Source Radosław Rzepecki
An abstract texture of black metal pipes (seamless).
Source V. Hartikainen
Derived from a corner decoration itself found as a jpg on Pixabay.
Source Firkin
From an image on opengameart.org shared by rubberduck.
Source Firkin
The image is a remix of "edo pattern-samekomon".I changed the color of dots from black to white and added BG in light-brown.
Source Yamachem
High detail stone wall with minor cracks and specks.
Source Projecteightyfive
Zero CC tileable Crackled Cement (streaks) texture, photographed and made by me. CC0
Source Sojan Janso
Paper pattern with small dust particles and 45-degree strokes.
Source Atle Mo
A huge one at 800x600px. Made from a photo I took going home after work.
Source Atle Mo
A seamlessly tile-able grunge background image.
Source V. Hartikainen
f you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Sort of like the Photoshop transparent background, but better!
Source Alex Parker
Looks like an old wall. I guess that’s it then?
Source Viahorizon
Remixed from a drawing in 'The March of Loyalty', Letitia MacClintock, 1884.
Source Firkin