A seamless pattern based on a square tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
A simple but elegant classic. Every collection needs one of these.
Source Christopher Burton
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
Horizontal and vertical lines on a light gray background.
Source Adam Anlauf
From a drawing in 'A Rolling Stone. A tale of wrongs and revenge', John Hartley, 1878.
Source Firkin
Just what the name says, paper fibers. Always good to have.
Source Heliodor jalba
Number 1 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
This is a seamless pattern which is derived from a flower petal image.
Source Yamachem
White fabric looking texture with some nice random wave features.
Source Hendrik Lammers
A car pattern?! Can it be subtle? I say yes!
Source Radosław Rzepecki
Prismatic Rounded Squares Grid 4 No Background
Source GDJ
A background pattern inspired by designs seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
There are quite a few grid patterns, but this one is a super tiny grid with some dust for good measure.
Source Dominik Kiss
That’s what it is, a dark dot. Or sort of carbon looking.
Source Tsvetelin Nikolov
The image depicts a seamless pattern made using a bird's face.
Source Yamachem
Remixed from a drawing in 'A Girl in Ten Thousand', Elizabeth Meade, 1896.
Source Firkin