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
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Prismatic Hexagonalism Pattern No Background
Source GDJ
A background pattern inspired by designs seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Remixed from an image that was uploaded to Pixabay by KirstenStar
Source Firkin
Design drawn in Paint.net, vectorised using Vector Magic and finished in Inkscape.
Source Firkin
Geometric lines are always hot, and this pattern is no exception.
Source Listvetra
Prismatic Hypnotic Pattern No Background
Source GDJ
Everyone loves a diamond, right? Make your site sparkle.
Source AJ Troxell
A playful triangle pattern with different shades of gray.
Source Dimitrie Hoekstra
Seamless Prismatic Geometric Pattern With Background
Source GDJ
From a drawing in 'Les Chroniqueurs de l'Histoire de France depuis les origines jusqu'au XVIe siècle', Henriette Witt, 1884.
Source Firkin
From a drawing in 'Navigations de Alouys de Cademoste.-La Navigation du Capitaine Pierre Sintre', Alvise da ca da Mosto, 1895.
Source Firkin
Seamless pattern the basic tile for which can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A free background pattern with abstract green tiles.
Source V. Hartikainen
An alternative colour scheme for the original background.
Source Firkin
Remixed from a vector adapted from a jpg on Pixabay. The tile this is constructed from can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
You can never get enough of these tiny pixel patterns with sharp lines.
Source Designova
This is the remix of "blue wave-seigaiha".The image depicts a seamless pattern of the front upper part of Japanese five yen coin which is used currently.This design represents a rice with ripe golden ears.
Source Yamachem
Remixed from a drawing in 'A Child of the Age', Francis Adams, 1894.
Source Firkin
The image depicts a seamless pattern of the design which includes a stylized lotus and a stylized crane.I referred to the original image in a book which is into public domain.
Source Yamachem