Based on several public domain drawings on Wikimedia Commons. This was formed from a rectangular tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i
Source Firkin
There are quite a few grid patterns, but this one is a super tiny grid with some dust for good measure.
Source Dominik Kiss
A new take on the black linen pattern. Softer this time.
Source Atle Mo
A seamless pattern based on a rectangular tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
CC0 and seamless wellington boot pattern.
Source SliverKnight
Zero CC tileable hard cover cells, skin like, book texture. 4K, Scanned and made by me CC0
Source Sojan Janso
Here is a new seamless wood texture for using as blog or website backgrounds.
Source V. Hartikainen
Formed from a tile based on a drawing from 'Viaggi d'un artista nell'America Meridionale', Guido Boggiani, 1895.
Source Firkin
Very simple, very blu(e). Subtle and nice.
Source Seb Jachec
I have no idea what J Boo means by this name, but hey – it’s hot.
Source j Boo
Formed by distorting a JPG from PublicDomainPictures
Source Firkin
This is so subtle I hope you can see it! Tweak at will.
Source Alexandre Naud
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
The image depicts an edo-era pattern called "same-komon" or "鮫小紋"which looks like a shark skin.The "same" in Japanese means shark in English.
Source Yamachem
A large (588x375px) sand-colored pattern for your ever-growing collection. Shrink at will.
Source Alex Tapein
Prismatic Polka Dots Mark II No Background
Source GDJ
More Japanese-inspired patterns, Gold Scales this time.
Source Josh Green
Remixed from a drawing that was uploaded to Pixabay by ractapopulous
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
A seamless pattern formed from miutopia's cakes on a tablecloth.
Source Firkin
A huge one at 800x600px. Made from a photo I took going home after work.
Source Atle Mo
A slightly more textured pattern, medium gray. A bit like a potato sack?
Source Bilal Ketab
A background pattern inspired by designs seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
It’s an egg, in the form of a pattern. This really is 2012.
Source Paul Phönixweiß