This could be a hippy vintage wallpaper.
Source Tileable Patterns
This is a remix of "flower seamless pattern".I rotated the original image by 90 degrees.This is a seamless pattern of flowers.These horizontal wavy lines are one of Edo patterns which is called "tatewaku or tachiwaku or 立湧" that represents uprising steam or vapor.
Source Yamachem
Not sure if this is related to the Nami you get in Google image search, but hey, it’s nice!
Source Dertig Media
A free background image with a seamless texture of cardboard. This texture of cardboard looks quite realistic, especially when is actually tiled.
Source V. Hartikainen
Number 5 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
The image depicts a pattern of regular hexagon.As I made to use it for myself,I want to others to use it.Speaking about the ratio of the image, height : width = 2 : √3(1.732...)Ridiculous to say,I realized later that this image is not honey comb pattern.I have to slide the second row.
Source Yamachem
Nice little grid. Would work great as a base on top of some other patterns.
Source Arno Gregorian
Feel free to download this "Dark Wood" background texture for your web site. The background tiles seamlessly!
Source V. Hartikainen
Prismatic Abstract Line Art Pattern Background 2
Source GDJ
A bit like smudged paint or some sort of steel, here is scribble light.
Source Tegan Male
Might not be super subtle, but quite original in its form.
Source Alex Smith
From a drawing in 'Danmarks Riges Historie af J. Steenstrup, Kr. Erslev, A. Heise, V. Mollerup, J. A. Fridericia, E. Holm, A. D. Jørgensen', 1897.
Source Firkin
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
You can never get enough of these tiny pixel patterns with sharp lines.
Source Designova
Derived from elements found in a floral ornament drawing on Pixabay.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
I know there is one here already, but this is sexy!
Source Gjermund Gustavsen
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
I love these crisp, tiny, super subtle patterns.
Source Badhon Ebrahim