Not so subtle. These tileable wood patterns are very useful.
Source Elemis
All good things come in threes, so I give you the third in my little concrete wall series.
Source Atle Mo
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
To get the tile this is made up from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
The first pattern on here using opacity. Try it on a site with a colored background, or even using mixed colors.
Source Nathan Spady
A good starting point for a cardboard pattern. This would work well in a variety of colors.
Source Atle Mo
The square tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Remixed from an image on Pixabay, the original having been uploaded by darkmoon1968.
Source Firkin
Never out of fashion and so much hotter than the 45º everyone knows, here is a sweet 60º line pattern.
Source Atle Mo
One more in the line of patterns inspired by Japanese/Asian styles. Smooth.
Source Kim Ruddock
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
High detail stone wall with minor cracks and specks.
Source Projecteightyfive
A seamless stone-like background for blogs or any other type of websites.
Source V. Hartikainen
This one is so simple, yet so good. And you know it. Has to be in the collection.
Source Gluszczenko
You don’t see many mid-tone patterns here, but this one is nice.
Source Joel Klein
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A seamless pattern formed from a sports car on clker.com. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Remixed from a JPG that was uploaded to Pixabay by susanlu4esm
Source Firkin
You can never get enough of these tiny pixel patterns with sharp lines.
Source Designova
A light background pattern with diagonal stripes. Here's a simple light striped background for you.
Source V. Hartikainen
Number 1 in a series of 5 beautiful patterns. Can be found in colors on the submitter’s website.
Source Janos Koos
This is the remix of "Strawberry Pattern Background" uploaded by "GDJ". Thanks. I realigned strawberries so as to get seamless and changed the BG color.
Source Yamachem