Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
From a drawing in 'Hundert Jahre in Wort und Bild', S. Stefan, 1899.
Source Firkin
Prismatic Triangular Seamless Pattern III With Background
Source GDJ
If you like it a bit trippy, this wave pattern might be for you.
Source Ian Soper
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
From a drawing in 'A Life Interest', Mrs Alexander, 1888.
Source Firkin
Scanned some rice paper and tiled it up for you. Enjoy.
Source Atle Mo
A very dark spotted twinkle pattern for your twinkle needs.
Source Badhon Ebrahim
Not strictly seamless in that opposite edges are not identical. But they do marry up to make an interesting pattern
Source Firkin
Remixed from a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
This one is amazing, truly original. Go use it!
Source Viahorizon
A lot of people like the icon patterns, so here’s one for your restaurant blog.
Source Andrijana Jarnjak
A pattern formed from a squared tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Just like the black maze, only in light gray. Duh.
Source Peax
A seamless pattern based on a square tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
A pattern derived from part of a fractal rendering in Paint.net.
Source Firkin
A free seamless background pattern for use on websites.
Source V. Hartikainen
Here's a repeatable texture that resembles a light green concrete wall or something similar.
Source V. Hartikainen
From a drawing in 'Jardyne's Wife', Charles Wills, 1891.
Source Firkin
Subtle scratches on a light gray background.
Source Andrey Ovcharov
A seamless light gray paper texture with horizontal double lines.
Source V. Hartikainen
It’s big, it’s gradient—and it’s square.
Source Brankic1979