Prismatic Groovy Concentric Background 3 No Black
Source GDJ
A version without colours blended together to give a different look.
Source Firkin
Vector version of a png that was uploaded to Pixabay by pencilparker
Source Firkin
A background pattern inspired by designs seen in 'Burghley. The Life of William Cecil', William Charlton, 1857.
Source Firkin
This background pattern contains a seamless texture of bark. It's not very realistic, but I think it looks quite nice.
Source V. Hartikainen
A pale orange background pattern with glossy groove stripes.
Source V. Hartikainen
Light gray pattern with an almost wall tile-like appearance.
Source Markus Tinner
Prismatic Groovy Concentric Background 4
Source GDJ
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
A slightly more textured pattern, medium gray. A bit like a potato sack?
Source Bilal Ketab
Dark squares with some virus-looking dots in the grid.
Source Hugo Loning
Retro Circles Background 4 No Black
Source GDJ
Zero CC tileable hard cover cells book texture, 4k, scanned and made by me. CC0
Source Sojan Janso
A background pattern with blue on white vertical stripes.
Source V. Hartikainen
This one looks like a cork panel. Feel free to use it as a tiled background on your blog or website.
Source V. Hartikainen
A seamless light gray paper texture with horizontal double lines.
Source V. Hartikainen
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Black version of a pattern that came out of playing with the 'light rays' plug-in for Paint.net
Source Firkin
Remixed from an image that was uploaded to Pixabay by Pixeline
Source Firkin
Love me some light mesh on a Monday. Sharp.
Source Wilmotte Bastien
Remixed from a drawing in 'The Canadian horticulturist', 1892
Source Firkin
A seamless texture traced from an image on opengameart.org shared by Scouser.
Source Firkin
Dark, crisp and subtle. Tiny black lines on top of some noise.
Source Wilmotte Bastien