Fabric-ish patterns are close to my heart. French Stucco to the rescue.
Source Christopher Buecheler
People seem to enjoy dark patterns, so here is one with some circles.
Source Atle Mo
It looks like a polished stone surface to me. Download it for free, as always.
Source V. Hartikainen
The tile this is based on was adapted from an image that was uploaded to Pixabay by frolicsomepl. It can be had in Inkscape by selecting the rectangle and using 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
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Drawn in Paint.net using the kaleidoscope plug-in and vectorised.
Source Firkin
A seamless pattern formed from background pattern 102
Source Firkin
A subtle shadowed checkered pattern. Increase the lightness for even more subtle sexiness.
Source Josh Green
I guess this is inspired by the city of Ravenna in Italy and its stone walls.
Source Sentel
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Looks like an old rug or a computer chip.
Source Patutin Sergey
Same as the black version, but now in shades of gray. Very subtle and fine grained.
Source Atle Mo
Not even 1kb, but very stylish. Gray thin lines.
Source Struck Axiom
Prismatic Geometric Pattern Background No Black
Source GDJ
Got some felt in my mailbox today, so I scanned it for you to use.
Source Atle Mo
A bit like smudged paint or some sort of steel, here is scribble light.
Source Tegan Male
Real snow that tiles, not easy. This is not perfect, but an attempt.
Source Atle Mo
A free background pattern with abstract green tiles.
Source V. Hartikainen
Prismatic Snowflakes Pattern No Background
Source GDJ
Might not be super subtle, but quite original in its form.
Source Alex Smith