As simple and subtle as it gets. But sometimes that’s just what you want.
Source Designova
Prismatic Snowflakes Pattern 3 No Background
Source GDJ
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
A pattern formed from a squared tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Bumps, highlight and shadows – all good things.
Source Badhon Ebrahim
The green fibers pattern will work very well in grayscale as well.
Source Matteo Di Capua
Colour version of the original pattern.
Source Firkin
The classic 45-degree diagonal line pattern, done right.
Source Jorick van Hees
Colour version of the original pattern.
Source Firkin
Prismatic Geometric Pattern Variation 2 With Background
Source GDJ
From a drawing in 'Uit de geschiedenis der Heilige Stede te Amsterdam', Yohannes Sterck, 1898.
Source Firkin
Not sure if this is related to the Nami you get in Google image search, but hey, it’s nice!
Source Dertig Media
Remixed from an image that was uploaded to Pixabay by Pixeline
Source Firkin
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
Remixed from a raster on Pixabay that was uploaded by ArtsyBee.
Source Firkin
Derived from an image that was uploaded to Pixabay by mdmelo.
Source Firkin
A seamless background pattern with a texture of wood planks. This wood background pattern has vertically arranged planks. You may try to rotate it 90°, to see how it will look like when the wood planks are arranged horizontally.
Source V. Hartikainen
On a large canvas you can see it tiling, but used on smaller areas, it’s beautiful.
Source Paul Phönixweiß
This reminds me of Game Cube. A nice light 3D cube pattern.
Source Sander Ottens
Not even 1kb, but very stylish. Gray thin lines.
Source Struck Axiom
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Prismatic Curved Diamond Pattern 6 No Background
Source GDJ
Prismatic Snowflakes Pattern No Background
Source GDJ
A seamless green background texture. The image is distributed under a Creative Commons License (like all of the images here).
Source V. Hartikainen