The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i.
Source Firkin
Heavy depth and shadows here, but might work well on some mobile apps.
Source Damian Rivas
The rectangular tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Background Wall, Art Abstract, Block Well & CC0 texture.
Source Ractapopulous
ZeroCC tileabel stone granite texture, edited from pixabay. CC0
Source Sojan Janso
Seamless , tileable CC-0 texture. Created by my own, feel free to use wherever you want!
Source Linolafett
Colour version that is close to the original drawing uploaded to Pixabay by pencilparker.
Source Firkin
From a drawing in 'Cassell's Library of English Literature', Henry Morley, 1883.
Source Firkin
From a drawing in 'Uit de geschiedenis der Heilige Stede te Amsterdam', Yohannes Sterck, 1898.
Source Firkin
Continuing the geometric trend, here is one more.
Source Mike Warner
Remixed from a drawing in 'A Girl in Ten Thousand', Elizabeth Meade, 1896.
Source Firkin
Fabric-ish patterns are close to my heart. French Stucco to the rescue.
Source Christopher Buecheler
More Japanese-inspired patterns, Gold Scales this time.
Source Josh Green
A topographic map like this has actually been requested a few times, so here you go!
Source Sam Feyaerts
A green background pattern with warped vertical stripes and a grunge look.
Source V. Hartikainen
Remixed from a raster on Pixabay, that was uploaded by ArtsyBee.
Source Firkin
Dark, square, clean and tidy. What more can you ask for?
Source Jaromír Kavan
A seamless green background texture. The image is distributed under a Creative Commons License (like all of the images here).
Source V. Hartikainen
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
Cubes as far as your eyes can see. You know, because they tile.
Source Jan Meeus
This is a grid, only it’s noisy. You know. Reminds you of those printed grids you draw on.
Source Vectorpile
A free green background pattern with a pattern of rhombuses on a seamless texture. Feel free to use it as a tiled background image on your web site.
Source V. Hartikainen
A pale yellow background pattern with vertical stripes. The stripes are partially faded. I think this background image turned out pretty well, especially those faded stripes.
Source V. Hartikainen
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin