Just to prove my point, here is a slightly modified dark version.
Source Atle Mo
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
One more brick pattern. A bit more depth to this one.
Source Benjamin Ward
I love these crisp, tiny, super subtle patterns.
Source Badhon Ebrahim
Not a flat you live inside, like in the UK – but a flat piece of cardboard.
Source Appleshadow
Here's a new paper-like background for free use on personal and commercial projects (this applies to all background patterns here).
Source V. Hartikainen
emixed from a JPG that was uploaded to Pixabay by Kyotime
Source Firkin
A background formed from an image of an old tile on the New York Metropolitan Museum of Art website. To get the base tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A seamless pattern the unit cell for which can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Here's an yet another seamless note paper texture for use as a background on websites.
Source V. Hartikainen
The rectangular tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Just to prove my point, here is a slightly modified dark version.
Source Atle Mo
Utilising a bird from s-light and some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
From a drawing in 'In an Enchanted Island', William Mallock, 1892.
Source Firkin
This was formed by distorting an image of a background on Pixabay.
Source Firkin
This was formed by distorting an image of a background on Pixabay.
Source Firkin
Retro Circles Background 7 No Black
Source GDJ
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
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
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