Super subtle indeed, a medium gray pattern with tiny dots in a grid.
Source Designova
A seamless texture of worn out "cardboard".
Source V. Hartikainen
Prismatic Hypnotic Pattern No Background
Source GDJ
A subtle shadowed checkered pattern. Increase the lightness for even more subtle sexiness.
Source Josh Green
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
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
Just what the name says, paper fibers. Always good to have.
Source Heliodor jalba
Prismatic Floral Pattern 3 Variation 3 No Background
Source GDJ
Almost like little fish shells, or dragon skin.
Source Graphiste
A seamless dark leather-like background texture with diagonal lines that look like stitches.
Source V. Hartikainen
Colorful Floral Background No Black
Source GDJ
More bright luxury. This is a bit larger than fancy deboss, and with a bit more noise.
Source Viszt Péter
Sounds French. Some 3D square diagonals, that’s all you need to know.
Source Graphiste
Not the most creative name, but it’s a good all-purpose light background.
Source Dmitry
This one is amazing, truly original. Go use it!
Source Viahorizon
Prismatic Geometric Pattern Background No Black
Source GDJ
Light gray grunge wall with a nice texture overlay.
Source Adam Anlauf
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin