Utilising some flowers from Almeidah. To get the unit tile, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Zero CC tileable hard cover cells book texture, 4k, scanned and made by me. CC0
Source Sojan Janso
A playful triangle pattern with different shades of gray.
Source Dimitrie Hoekstra
A free background image with a seamless texture of cardboard. This texture of cardboard looks quite realistic, especially when is actually tiled.
Source V. Hartikainen
A seamless pattern based on a tile that can be achieved by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Remixed from a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892. The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Original minus the background
Source Firkin
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
Don’t look at this one too long if you’re high on something.
Source Luuk van Baars
I’m not going to use the word Retina for all the new patterns, but it just felt right for this one. Huge wood pattern for ya’ll.
Source Atle Mo
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
The image depicts a seamless pattern of a Japanese family crest called "chidori" in Japanese .A chidori in Japanese means a plover in English.
Source Yamachem
From a drawing in 'Uit de geschiedenis der Heilige Stede te Amsterdam', Yohannes Sterck, 1898.
Source Firkin
Psychedelic Geometric Background No Black
Source GDJ
Bright gray tones with a hint of some metal surface.
Source Hendrik Lammers
Looks a bit like concrete with subtle specks spread around the pattern.
Source Mladjan Antic
As far as fabric patterns goes, this is quite crisp.
Source Heliodor Jalba
This one needs to be used in small areas; you can see it repeat.
Source Luca
Abstract Geometric Monochrome Pattern Prismatic No Background
Source GDJ
Floral patterns will never go out of style, so enjoy this one.
Source Lasma
A seamlessly tileable pink background texture.
Source V. Hartikainen
Turn your site into a dragon with this great scale pattern.
Source Alex Parker
A huge one at 800x600px. Made from a photo I took going home after work.
Source Atle Mo