A free seamless background image with a texture of dark red "canvas". It should look very nice on web sites.
Source V. Hartikainen
This one takes you back to math class. Classic mathematic board underlay.
Source Josh Green
The image depicts polka dot seamless pattern.
Source Yamachem
This ladies and gentlemen, is texturetastic! Love it.
Source Adam Pickering
The image depicts meshed silhouettes of various things.The original image is an OCAL clipart called "Enter FOSSASIA 2016 #IoT T-shirt Design Contest" uploaded by "openclipart".Thanks.
Source Yamachem
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
A chequerboard pattern with a fruit theme. The fruits are from a posting by inkscapeforum.it.
Source Firkin
Remixed from a drawing in 'The Canadian horticulturist', 1892
Source Firkin
A seamless marble-like texture colored in light blue.
Source V. Hartikainen
Submitted in a cream color, but you know how I like it.
Source Devin Holmes
Basket Fibers, Basket Texture, Braid Background style CC0 texture.
Source 1A-Photoshop
A repeating background of thick textured paper. Actually, it turned out to look like something between a paper and fabric.
Source V. Hartikainen
From a drawing in 'Artists and Arabs', Henry Blackburn, 1868
Source Firkin
The tile this is formed from can be retrieved in Inkscape by selecting the rectangle and using shift+alt+i
Source Firkin
Derived from a corner decoration itself found as a jpg on Pixabay.
Source Firkin
Formed from a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A series of 5 patterns. That’s what the P stands for, if you didn’t guess it.
Source Dima Shiper
Dark, square, clean and tidy. What more can you ask for?
Source Jaromír Kavan
Inspired by a pattern seen on a public domain image of a very old tile. To get the unit cell, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
From a drawing in 'Handbook of the excursions proposed to be made by the Lincoln Diocesan Architectural Society, on the 27th and 28th of May, 1857', Edward Trollope, 1857.
Source Firkin
Could remind you a bit of those squares in Super Mario Bros, yeh?
Source Jeff Wall
Same as the black version, but now in shades of gray. Very subtle and fine grained.
Source Atle Mo
A topographic map like this has actually been requested a few times, so here you go!
Source Sam Feyaerts
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin