To get the repeating unit, select the rectangle in Inkscape and use shift+alt+i
Source Firkin
Black brick wall pattern. Brick your site up!
Source Alex Parker
Background formed from the original with an emboss effect.
Source Firkin
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
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
Remixed from a drawing in 'A Girl in Ten Thousand', Elizabeth Meade, 1896.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Seamless pattern formed from a square tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Real snow that tiles, not easy. This is not perfect, but an attempt.
Source Atle Mo
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
A repeating background for websites with a texture of black groove stripes.
Source V. Hartikainen
As the original image 's page size is too large for its image size, I remixed it.
Source Yamachem
Simple gray checkered lines, in light tones.
Source Radosław Rzepecki
Inspired by a drawing in 'Kulturgeschichte', Freidrich Hellwald, 1896.
Source Firkin
This was formed by distorting an image of a background on Pixabay.
Source Firkin
Dark, square, clean and tidy. What more can you ask for?
Source Jaromír Kavan
Derived from an image that was uploaded to Pixabay by Darkmoon1968
Source Firkin
Background Wall, Art Abstract, Block Well & CC0 texture.
Source Ractapopulous
A simple example on using clones. You can generate a nice base for a pattern fill quickly with it.
Source Lazur URH
A free seamless background image with a texture of dark red "canvas". It should look very nice on web sites.
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 seamless pattern that includes the original tile (go to Objects / Pattern / Pattern To Objects in Inkscape's menu to extract it).
Source GDJ