From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Sharp but soft triangles in light shades of gray.
Source Pixeden
A floral background formed from numerous clones of flower 117.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Background Wall, Art Abstract, Blue Well & CC0 texture.
Source Ractapopulous
Not the Rebel alliance, but a dark textured pattern.
Source Hendrik Lammers
This one resembles a black concrete wall when is tiled. It should look great, at least with dark website themes.
Source V. Hartikainen
If you don’t like cream and pixels, you’re in the wrong place.
Source Mizanur Rahman
Abstract Ellipses Background Grayscale
Source GDJ
Greyscale version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
Prismatic Abstract Geometric Background derived from an image on Pixabay.
Source GDJ
A smooth mid-tone gray, or low contrast if you will, linen pattern.
Source Jordan Pittman
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
This background pattern looks like bamboo to me. Feel free to download it for your website (for your blog perhaps?).
Source V. Hartikainen
Carbon fiber is never out of fashion, so here is one more style for you.
Source Alfred Lee
A bit like some carbon, or knitted netting if you will.
Source Anna Litvinuk
CC0 and seamless wellington boot pattern.
Source SliverKnight
Remixed from a drawing in 'The Canadian horticulturist', 1892
Source Firkin
Not so subtle. These tileable wood patterns are very useful.
Source Elemis
This is so subtle: We’re talking 1% opacity. Get your squint on!
Source Atle Mo
A seamless light gray paper texture with horizontal double lines.
Source V. Hartikainen