The unit cell for this seamless pattern can be had 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
Some rectangles, a bit of dust and grunge, plus a hint of concrete.
Source Atle Mo
Made by distorting a simple pattern using the 'sin waves' plugin for Paint.net and vectorising in Vector Magic
Source Firkin
A playful triangle pattern with different shades of gray.
Source Dimitrie Hoekstra
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
Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A free black metallic background pattern. Here's a new pattern I made that looks metallic.
Source V. Hartikainen
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Prismatic Abstract Geometric Background 4 No Black
Source GDJ
From a drawing in 'Uit de geschiedenis der Heilige Stede te Amsterdam', Yohannes Sterck, 1898.
Source Firkin
Zero CC tileable seed texture, edited by me to be seamless from a Pixabay image. CC0
Source Sojan Janso
A light gray wall or floor (you decide) of concrete.
Source Atle Mo
emixed from a JPG that was uploaded to Pixabay by Kyotime
Source Firkin
Uses spirals from Pixabay. To get the basic tile select the rectangle in Inkscape and use shift+alt+i
Source Firkin
Remixed from a JPG that was uploaded to Pixabay by theasad121
Source Firkin
This was formed by distorting an image of a background on Pixabay.
Source Firkin
Inspired by a drawing in 'Poems', James Smith, 1881.
Source Firkin
A light gray fabric pattern with faded vertical stripes.
Source V. Hartikainen
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i
Source Firkin
Sort of like the Photoshop transparent background, but better!
Source Alex Parker
A light brushed aluminum pattern for your pleasure.
Source Tim Ward
The image depicts the Japanese Edo pattern called "seigaiha" or "青海波" meaning "blue -sea- wave".I hope it's suitable for the summer season.
Source Yamachem
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 a drawing in 'The Canadian horticulturist', 1892
Source Firkin
Prismatic Polka Dots 3 No Background
Source GDJ
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin