From a drawing in 'Hyde Park from Domesday-Book to date', John Ashton, 1896.
Source Firkin
A grid of squares with green colours. Since the colours are randomly distributed it is automatically seamless.
Source Firkin
A simple but elegant classic. Every collection needs one of these.
Source Christopher Burton
Bright gray tones with a hint of some metal surface.
Source Hendrik Lammers
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
To get the repeating unit, select the rectangle in Inkscape and use shift+alt+i
Source Firkin
Pixel by pixel, sharp and clean. Very light pattern with clear lines.
Source M.Ashok
A white version of the very popular linen pattern.
Source Ant Ekşiler
Sort of like the Photoshop transparent background, but better!
Source Alex Parker
The rectangular tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
One more in the line of patterns inspired by Japanese/Asian styles. Smooth.
Source Kim Ruddock
The texture of this background image has some similarities with leather, and it's colored in a dark brown color. So, if you are looking for a dark brown background image for your website, this may be an option for you.
Source V. Hartikainen
From a drawing in 'The Quiver of Love', Walter Crane, 1876
Source Firkin
Prismatic Groovy Concentric Background
Source GDJ
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
A very slick dark rubber grip pattern, sort of like the grip on a camera.
Source Sinisha
A version without colours blended together to give a different look.
Source Firkin
Remixed from a JPG that was uploaded to Pixabay by theasad121
Source Firkin
Some dark 45 degree angles creating a nice pattern. Huge.
Source Dark Sharp Edges
Geometric triangles seem to be quite hot these days.
Source Pixeden
Prismatic Groovy Concentric Background 5
Source GDJ
A mid-tone gray pattern with some cement looking texture.
Source Hendrik Lammers
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Remixed from a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
Produced using the clouds, flames and glass blocks plug-ins in Paint.net and the resulting .PNG vectorised with Vector Magic.
Source Firkin