From a drawing in 'Gately's World's Progress', Charles Beale, 1886.
Source Firkin
This background pattern has futuristic look. So, maybe it could be used on websites or blogs dedicated to video games?!
Source V. Hartikainen
From a drawing in 'Studies for Stories', Jean Ingelow, 1864.
Source Firkin
Nicely crafted paper pattern, although a bit on the large side (500x593px).
Source Blaq Annabiosis
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Here's a brown background pattern with subtle stripes. I hope you'll like the color. If not, feel free to change it using an image editor, if you know how of course. Personally, I'm using GIMP to create these backgrounds.
Source V. Hartikainen
An abstract Background pattern of purple twisty patterns.
Source TikiGiki
A seamless pattern from a tile drawn in Paint.net and vectorised in Vector Magic
Source Firkin
A light gray background pattern with seamless fabric-like texture and almost unnoticeable stripes.
Source V. Hartikainen
This background pattern contains a texture of yellow wood planks. I think it looks quite original.
Source V. Hartikainen
Adapted heavily from a JPG that was uploaded to Pixabay by Viscious-Speed.
Source Firkin
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Has nothing to do with toast, but it’s nice and subtle.
Source Pippin Lee
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
The original enhanced with one of Inkscapes's filters.
Source Firkin
A textured blue background pattern with vertical stripes.
Source V. Hartikainen
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Snap! It’s a pattern, and it’s not grayscale! Of course you can always change the color in Photoshop.
Source Atle Mo
Floral patterns might not be the hottest thing right now, but you never know when you need it!
Source Lauren
Zero CC tileable hard cover green book, scanned and made by me. CC0
Source Sojan Janso
Actually, there's no clouds in it, but I think it looks quite nice.
Source V. Hartikainen
A seamless green background texture. The image is distributed under a Creative Commons License (like all of the images here).
Source V. Hartikainen
Found on the ground in french cafe in kunming, Yunnan, china
Source Rejon
One more in the line of patterns inspired by Japanese/Asian styles. Smooth.
Source Kim Ruddock