The act or state of corrugating or of being corrugated, a wrinkle; fold; furrow; ridge.
Source Anna Litvinuk
This light yellow background pattern consists of an irregular pattern of spots. Here's a light background pattern with yellowish tint.
Source V. Hartikainen
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Inspired by a drawing in 'Kulturgeschichte', Freidrich Hellwald, 1896.
Source Firkin
This ons is quite old school looking. Retro, even. I like it.
Source Arno Declercq
A seamless pale yellow paper background with a pattern of animal tracks.
Source V. Hartikainen
Retro Circles Background 8 No Black
Source GDJ
An interesting dark spotted pattern at an angle.
Source Hendrik Lammers
The tile this is based on can be had by selecting the rectangle in Inkscape and using shift+alt+i
Source Firkin
Abstract Tiled Background Extended 12
Source GDJ