Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Simple combination of stripy squares with their negatively coloured counterparts
Source Firkin
An emulated “transparent” background pattern, like that of all kinds of computer graphics software.
Source AdamStanislav
From a drawing in 'At home', J. Sowerby, J. Crane and T. Frederick, 1881.
Source Firkin
Seamless pattern formed from a tile that can be had by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
A seamless pattern formed from miutopia's cakes on a tablecloth.
Source Firkin
This background pattern looks like bamboo to me. Feel free to download it for your website (for your blog perhaps?).
Source V. Hartikainen
A seamless pattern based on a rectangular tile that can be retrieved in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Alternative colour scheme for the original floral pattern.
Source Firkin
Oh yes, it happened! A pattern in full color.
Source Atle Mo
Prismatic Polyskelion Pattern No Background
Source GDJ
CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Everyone needs some stardust. Sprinkle it on your next project.
Source Atle Mo
An abstract texture of water. It's not perfect, but will do. You may download if you like it.
Source V. Hartikainen
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
Background formed from the original with an emboss effect.
Source Firkin
A large (588x375px) sand-colored pattern for your ever-growing collection. Shrink at will.
Source Alex Tapein
A free repetitive background with a dark concrete wall like texture. This one may be used in dark web site designs.
Source V. Hartikainen
Derived from a JPG that was uploaded to Pixabay by ractapopulous
Source Firkin
This is indeed a bit strange, but here’s to the crazy ones!
Source Christopher Buecheler