One more sharp little tile for you. Subtle circles this time.
Source Blunia
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
The image depicts a seamless pattern of pine tree leaves.
Source Yamachem
A version without colours blended together to give a different look.
Source Firkin
Subtle scratches on a light gray background.
Source Andrey Ovcharov
This one is quite simple in design, it consists of vertical stripes layered on top of a seamless texture.
Source V. Hartikainen
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Might not be super subtle, but quite original in its form.
Source Alex Smith
Prismatic Curved Diamond Pattern 7 No Background
Source GDJ
This is a seamless pattern which is derived from a flower petal image.
Source Yamachem
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
A dark background pattern/texture of a dimpled metal plate.
Source V. Hartikainen
Seamless Prismatic Pythagorean Line Art Pattern No Background. A seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).
Source GDJ
Sort of like the back of a wooden board. Light, subtle, and stylish, just the way we like it!
Source Nikolalek
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
If you want png files of this u can download them here : viscious-speed.deviantart.com/gallery/27635117
Source Viscious-Speed
Prismatic Hexagonalism Pattern No Background
Source GDJ
A light brushed aluminum pattern for your pleasure.
Source Tim Ward
This background pattern looks like bamboo to me. Feel free to download it for your website (for your blog perhaps?).
Source V. Hartikainen
Looks a bit like concrete with subtle specks spread around the pattern.
Source Mladjan Antic
Carbon fiber is never out of fashion, so here is one more style for you.
Source Alfred Lee
And some more testing, this time with Seamless Studio. It’s Robots FFS!
Source Seamless Studio
Free tiled background with colorful stripes and white splatter.
Source V. Hartikainen
A dark metallic background with a pattern of stamped dots. Here's a dark "metallic" background pattern for you.
Source V. Hartikainen