Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
Background Wall, Art Abstract, Block Well & CC0 texture.
Source Ractapopulous
A seamless gray background texture suitable for use on websites. To me, it has the look of stone. Feel free to modify it to meet your needs (by making it a bit lighter or darker, for example).
Source V. Hartikainen
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin
Bright Multicolored Floral Background by Karen Arnold from PDP.
Source GDJ
To get the tile this is based on, select the rectangle in Inkscape and use 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
Remixed from a drawing in 'The March of Loyalty', Letitia MacClintock, 1884.
Source Firkin
Dark, lines, noise, tactile. You get the drift.
Source Anatoli Nicolae
I know there is one here already, but this is sexy!
Source Gjermund Gustavsen
Prismatic Abstract Geometric Background 3
Source GDJ
Geometric triangles seem to be quite hot these days.
Source Pixeden
Prismatic Groovy Concentric Background 5 No Black
Source GDJ
It’s big, it’s gradient—and it’s square.
Source Brankic1979
From a design found in 'History of the Virginia Company of London; with letters to and from the first Colony, never before printed', Edward Neill, 1869.
Source Firkin
Derived from a PNG that was uploaded to Pixabay by nutkitten
Source Firkin
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
A seamless texture of a rough concrete surface.
Source V. Hartikainen
A seamless green background texture. The image is distributed under a Creative Commons License (like all of the images here).
Source V. Hartikainen
A dark pattern made out of 3×3 circles and a 1px shadow. This works well as a carbon texture or background.
Source Atle Mo
This seamless background image should look nice on websites. It has a dark blue gray texture with vertical stripes, it tiles seamlessly and, like all of the background images here, it's free. So, if you like it, take it!
Source V. Hartikainen
Abstract Tiled Background Extended 8
Source GDJ
This one is so simple, yet so good. And you know it. Has to be in the collection.
Source Gluszczenko