From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
A floral background formed from numerous clones of flower 117.
Source Firkin
A seamless light gray paper texture with horizontal double lines.
Source V. Hartikainen
This is the remix of "Strawberry Pattern Background" uploaded by "GDJ". Thanks. I realigned strawberries so as to get seamless and changed the BG color.
Source Yamachem
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
I love these crisp, tiny, super subtle patterns.
Source Badhon Ebrahim
A seamless pattern formed from a rectangular tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Prismatic Curved Diamond Pattern No Background
Source GDJ
A comeback for you: the popular Escheresque, now in black.
Source Patten
This seamless web background texture looks like gray stone. It's great for using as a background image on web pages, or on some of their elements. Anyway, I hope you will find use for it.
Source V. Hartikainen
A monochrome pattern from a tile that can be had by selecting the rectangle in Inkscaope and using shift+alt+i
Source Firkin
The first pattern on here using opacity. Try it on a site with a colored background, or even using mixed colors.
Source Nathan Spady
Remixed from a drawing in 'A Child of the Age', Francis Adams, 1894.
Source Firkin
Might not be super subtle, but quite original in its form.
Source Alex Smith
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
A seamless background texture of old cardboard.
Source V. Hartikainen
Derived from an image that was uploaded to Pixabay by Kaz
Source Firkin
Zero CC tileable seed texture, edited by me to be seamless from a Pixabay image. CC0
Source Sojan Janso
Derived from an image that was uploaded to Pixabay by darkmoon1968
Source Firkin
Continuing the geometric trend, here is one more.
Source Mike Warner