CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Love me some light mesh on a Monday. Sharp.
Source Wilmotte Bastien
Dark wooden pattern, given the subtle treatment. based on texture from Cloaks. https://cloaks.deviantart.com
Source Atle Mo
This one could be the shirt of a golf player. Angled lines in different thicknesses.
Source Olivier Pineda
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
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
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Prismatic Groovy Concentric Background 4 No Black
Source GDJ
A heavy hitter at 400x400px, but lovely still.
Source Breezi
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
This is the remix of an OCAL clipart called "Rain on Window" uploaded by "pagarmidna".Thanks.This is a seamless pattern of raindrops.
Source Yamachem
Nice and simple crossed lines in dark gray tones.
Source Stefan Aleksić
Derived from elements found in a floral ornament drawing on Pixabay.
Source Firkin
A version without colours blended together to give a different look.
Source Firkin
Sharp diamond pattern. A small 24x18px tile.
Source Tom Neal
A seamless pattern from a tile made from a jpg on Pixabay. To get the tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
A free seamless background with pink spots.
Source V. Hartikainen
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
From an image on opengameart.org shared by rubberduck.
Source Firkin
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
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