Super subtle indeed, a medium gray pattern with tiny dots in a grid.
Source Designova
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
Has nothing to do with toast, but it’s nice and subtle.
Source Pippin Lee
Zero CC tillable hard cover red book with X shape marks. Scanned and made by me.
Source Sojan Janso
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
Produced using the clouds, flames and glass blocks plug-ins in Paint.net and the resulting .PNG vectorised with Vector Magic.
Source Firkin
A seamless gray background texture suitable for use on websites. To me, it has the look of stone. Feel free to modify it to meet your needs (by making it a bit lighter or darker, for example).
Source V. Hartikainen
No relation to the band, but damn it’s subtle!
Source Thomas Myrman
A seamless pattern formed from a square tile. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
The name tells you it has curves. Oh yes, it does!
Source Peter Chon
Kaleidoscope Prismatic Abstract No Background
Source GDJ
Prismatic Abstract Geometric Background 5 No Black
Source GDJ
Paper pattern with small dust particles and 45-degree strokes.
Source Atle Mo
A background formed from an image of an old tile on the New York Metropolitan Museum of Art website. To get the base tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Remixed from a drawing in 'The March of Loyalty', Letitia MacClintock, 1884.
Source Firkin
Abstract Ellipses Background Grayscale
Source GDJ
No relation to the band, but damn it’s subtle!
Source Thomas Myrman
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A simple bump filter made upon request at irc #inkscape at freenode. Made a screen capture of the making here: https://youtu.be/TGAWYKVLxQw
Source Lazur URH
A seamless tessellation pattern. To get the tile this is formed from, select the pattern in Inkscape and use shift+alt+i.
Source Firkin
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
Super dark, crisp and detailed. And a Kill Bill reference.
Source Badhon Ebrahim
Seamless Prismatic Pythagorean Line Art Pattern No Background. A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).
Source GDJ
Derived from an image that was uploaded to Pixabay by pugmom40
Source Firkin
This seamless background image should look nice on websites. It has a dark blue gray texture with vertical stripes, it tiles seamlessly and, like all of the background images here, it's free. So, if you like it, take it!
Source V. Hartikainen