Here's a subtle marble-like background for use on websites.
Source V. Hartikainen
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A lovely light gray pattern with stripes and a dash of noise.
Source V. Hartikainen
A version without colours blended together to give a different look.
Source Firkin
Actually, there's no clouds in it, but I think it looks quite nice.
Source V. Hartikainen
Wild Oliva or Oliva Wilde? Darker than the others, sort of a medium dark pattern.
Source Badhon Ebrahim
I took the liberty of using Dmitry’s pattern and made a version without perforation.
Source Atle Mo
A fun-looking elastoplast/band-aid pattern. A hint of orange tone in this one.
Source Josh Green
Remixed from a design seen in 'Burghley. The Life of William Cecil', William Charlton, 1857. The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
The image depicts meshed silhouettes of various things.The original image is an OCAL clipart called "Enter FOSSASIA 2016 #IoT T-shirt Design Contest" uploaded by "openclipart".Thanks.
Source Yamachem
A tile-able background for websites with paper-like texture and a grid pattern layered on top of it.
Source V. Hartikainen
More Japanese-inspired patterns, Gold Scales this time.
Source Josh Green
Remixed from a drawing in 'Hungary. A guide book. By several authors', 1890.
Source Firkin
A heavy hitter at 400x400px, but lovely still.
Source Breezi
Hey, you never know when you’ll need a bird pattern, right?
Source Pete Fecteau
This is sort of fresh, but still feels a bit old school.
Source Martuchox
You don’t see many mid-tone patterns here, but this one is nice.
Source Joel Klein
Seamless SVG vector and JPG backgrounds with faded diagonal stripes. The colors are editable.
Source V. Hartikainen
Remixed from a drawing that was uploaded to Pixabay by ractapopulous
Source Firkin
Zero CC tileable ground (#2) cracked, crackled texture, made by me. CC0
Source Sojan Janso
A version without colours blended together to give a different look.
Source Firkin
A pattern derived from part of a fractal rendering in Paint.net.
Source Firkin