This is so subtle: We’re talking 1% opacity. Get your squint on!
Source Atle Mo
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A smooth mid-tone gray, or low contrast if you will, linen pattern.
Source Jordan Pittman
Pattern #100! A black classic knit-looking pattern.
Source Factorio.us Collective
One of the few full-color patterns here, but this one was just too good to pass up.
Source Alexey Usoltsev
Three shades of gray makes this pattern look like a small carbon fiber surface. Great readability even for small fonts.
Source Atle Mo
Detailed but still subtle and quite original. Lovely gray shades.
Source Kim Ruddock
This one is quite simple in design, it consists of vertical stripes layered on top of a seamless texture.
Source V. Hartikainen
Lovely pattern with splattered vintage speckles.
Source David Pomfret
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 unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Medium gray fabric pattern with 45-degree lines going across.
Source Atle Mo
Remixed from a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Seamless Olive Green Web Background Image
Source V. Hartikainen
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
The image depicts a seamless pattern of a Japanese family crest called "chidori" in Japanese .A chidori in Japanese means a plover in English.
Source Yamachem
Prismatic Groovy Concentric Background 2 No Black
Source GDJ
A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A repeating background for websites with a texture of black groove stripes.
Source V. Hartikainen
Smooth Polaroid pattern with a light blue tint.
Source Daniel Beaton