If you like it a bit trippy, this wave pattern might be for you.
Source Ian Soper
Heavily remixed from a drawing in 'Barbara Leybourne; a story of eighty years ago', Sarah Hamer, 1889.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Prismatic Groovy Concentric Background 2
Source GDJ
Bright gray tones with a hint of some metal surface.
Source Hendrik Lammers
Remixed from a drawing in 'Works. Popular edition', John Ruskin, 1886.
Source Firkin
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
A seamless pattern from a tile made from a jpg on Pixabay. To get the tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
A heavy hitter at 400x400px, but lovely still.
Source Breezi
Stefan is hard at work, this time with a funky pattern of squares.
Source Stefan Aleksić
This is indeed a bit strange, but here’s to the crazy ones!
Source Christopher Buecheler
Background pattern made in "Grunge-Like" style. Available in both SVG and JPG formats. Edit to your needs then click the download button.
Source V. Hartikainen
From a drawing in 'Worsborough; its historical associations and rural attractions', Joseph Wilkinson, 1879.
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
From a drawing in 'Bond Slaves. The story of a struggle.', Isabella Varley, 1893.
Source Firkin
Luxury pattern, looking like it came right out of Paris.
Source Daniel Beaton
Dark wooden pattern, given the subtle treatment. based on texture from Cloaks. https://cloaks.deviantart.com
Source Atle Mo
Small dots with minor circles spread across to form a nice mosaic.
Source John Burks
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
From a drawing in 'Studies for Stories', Jean Ingelow, 1864.
Source Firkin
To get the tile this is formed from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
There are many carbon patterns, but this one is tiny.
Source Designova
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
From a drawing in 'Gately's World's Progress', Charles Beale, 1886.
Source Firkin
Prismatic Floral Background No Black
Source GDJ