A free background image with a seamless texture of cardboard. This texture of cardboard looks quite realistic, especially when is actually tiled.
Source V. Hartikainen
You could get a bit dizzy from this one, but it might come in handy.
Source Dertig Media
Kaleidoscope Prismatic Abstract No Background
Source GDJ
Hey, you never know when you’ll need a bird pattern, right?
Source Pete Fecteau
To get the tile this is made up from select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
A slightly more textured pattern, medium gray. A bit like a potato sack?
Source Bilal Ketab
Derived from an image that was uploaded to Pixabay by darkmoon1968
Source Firkin
Prismatic Curved Diamond Pattern 2 No Background
Source GDJ
A seamless pattern the starting point for which was a 'rainbow twist' texture in Paint.net.
Source Firkin
From a drawing in 'Resa i Afrika, genom Angola, Ovampo och Damaraland', P. Moller, 1899.
Source Firkin
The original enhanced with some gradients.
Source Firkin
Zero CC tileable yellow craft paper; scanned and made by me. CC0
Source Sojan Janso
To get the tile this is based on select the rectangle in Inkscape and use shift-alt-i
Source Firkin
A free seamless background pattern for use on websites.
Source V. Hartikainen
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
The act or state of corrugating or of being corrugated, a wrinkle; fold; furrow; ridge.
Source Anna Litvinuk
Lovely light gray floral motif with some subtle shades.
Source GraphicsWall
Luxury pattern, looking like it came right out of Paris.
Source Daniel Beaton
ZeroCC tileabel stone granite texture, edited from pixabay. CC0
Source Sojan Janso
A simple example on using clones. You can generate a nice base for a pattern fill quickly with it.
Source Lazur URH
Drawn in Paint.net using the kaleidoscope plug-in and vectorised.
Source Firkin
From a drawing in 'Sun Pictures of the Norfolk Broads', Ernest Suffling, 1892.
Source Firkin
A seamless pattern formed from a rectangular tile. The tile can be retrieved by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin
To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
People seem to enjoy dark patterns, so here is one with some circles.
Source Atle Mo