CC0 and a seamless pattern from a tile drawn in Paint.net .
Source SliverKnight
Prismatic Abstract Geometric Background 4
Source GDJ
A free background pattern with abstract green tiles.
Source V. Hartikainen
Lovely pattern with some good-looking non-random noise lines.
Source Zucx
Smooth Polaroid pattern with a light blue tint.
Source Daniel Beaton
Prismatic Polka Dots Mark II No Background
Source GDJ
Remixed from a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
Fix and cc0 to get the tile this is based on.
Source SliverKnight
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A seamless paper background texture colored in pale yellow. This seamless texture is ideal for those who need a yellow background image for their website. The texture resembles paper.
Source V. Hartikainen
Nicely crafted paper pattern, although a bit on the large side (500x593px).
Source Blaq Annabiosis
Zero CC tileable bark texture, photographed and made by me. CC0
Source Sojan Janso
I have no idea what J Boo means by this name, but hey – it’s hot.
Source j Boo
One more brick pattern. A bit more depth to this one.
Source Benjamin Ward
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
A repeating background with dark brown stone-like texture and abstract pattern that looks like tree trunks.
Source V. Hartikainen
Remixed from a drawing in 'An Index to Deering's Nottinghamia Vetus et Nova', Rupert Chicken, 1899. The unit tile can be had by selecting the rectangle in Inkscape and using shift-alt-i
Source Firkin
An abstract texture of black metal pipes (seamless).
Source V. Hartikainen
From a drawing in 'Heroes of North African Discovery', Nancy Meugens, 1894.
Source Firkin
Alternative colour scheme for the original floral pattern.
Source Firkin
Submitted as a black pattern, I made it light and a few steps more subtle.
Source Andy
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin