Super simple but very nice indeed. Gray with vertical stripes.
Source Merrin Macleod
The image depicts a seamless pattern which includes hexagonally-aligned gourds with BG in light-brown.
Source Yamachem
Zero CC tileable yellow craft paper; scanned and made by me. CC0
Source Sojan Janso
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 comeback for you: the popular Escheresque, now in black.
Source Patten
Prismatic Groovy Concentric Background
Source GDJ
This beige background pattern resembles a concrete wall with engravings or something similar to it.
Source V. Hartikainen
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Dark blue concrete wall with some small dust spots.
Source Atle Mo
Honestly, who does not like a little pipe and mustache?
Source Luca Errico
An interesting dark spotted pattern at an angle.
Source Hendrik Lammers
Abstract Tiled Background Extended 6
Source GDJ
A subtle shadowed checkered pattern. Increase the lightness for even more subtle sexiness.
Source Josh Green
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
Everyone needs some stardust. Sprinkle it on your next project.
Source Atle Mo
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
A seamless pattern with green and yellow diagonal lines on top of a white dotted background.
Source V. Hartikainen
Fake or not, it’s quite luxurious.
Source Factorio.us Collective
Prismatic Abstract Line Art Pattern Background 2
Source GDJ
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin