Might not be super subtle, but quite original in its form.
Source Alex Smith
Number 1 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
The tile this is based on can be retrieved by selecting the rectangle in Inkscape and using shift+alt+i.
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
Zero CC tillable hard cover red book with X shape marks. Scanned and made by me.
Source Sojan Janso
This was formed by distorting an image of a background on Pixabay.
Source Firkin
Remixed from a drawing in 'The Canadian horticulturist', 1892
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 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
If you like it a bit trippy, this wave pattern might be for you.
Source Ian Soper
Prismatic Rounded Squares Grid 3 No Background
Source GDJ
Like the name says, light and gray, with some small dots and circles.
Source Brenda Lay
No relation to the band, but damn it’s subtle!
Source Thomas Myrman
Sharp pixel pattern looking like some sort of fabric.
Source Dmitry
From a design found in 'History of the Virginia Company of London; with letters to and from the first Colony, never before printed', Edward Neill, 1869.
Source Firkin
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
Prismatic Snowflakes Pattern No Background
Source GDJ
Background pattern made in "Grunge-Like" style. Available in both SVG and JPG formats. Edit to your needs then click the download button.
Source V. Hartikainen
Lovely pattern with splattered vintage speckles.
Source David Pomfret