The tile this fill pattern is based on can be had by using shift+alt+i on the rectangle.
Source Firkin
A good starting point for a cardboard pattern. This would work well in a variety of colors.
Source Atle Mo
Plywood Web Background background image for use in web design.
Source V. Hartikainen
It’s okay to be square! A nice light gray pattern with random squares.
Source Waseem Dahman
A re-make of the Gradient Squares pattern.
Source Dimitar Karaytchev
From a design found in 'History of the Virginia Company of London; with letters to and from the first Colony, never before printed', Edward Neill, 1869.
Source Firkin
From a drawing in 'Line and form', Walter Crane, 1914.
Source Firkin
Uses spirals from Pixabay. To get the basic tile select the rectangle in Inkscape and use shift+alt+i
Source Firkin
From a drawing in 'Art Embroidery', M.S. Lockwood and E. Glaister, 1878.
Source Firkin
Prismatic Abstract Geometric Background 5
Source GDJ
The act or state of corrugating or of being corrugated, a wrinkle; fold; furrow; ridge.
Source Anna Litvinuk
If you don’t like cream and pixels, you’re in the wrong place.
Source Mizanur Rahman
Here's a new paper-like background for free use on personal and commercial projects (this applies to all background patterns here).
Source V. Hartikainen
From a drawing in 'Maidenhood; or, the Verge of the Stream', Laura Jewry, 1876.
Source Firkin
Here's a subtle marble-like background for use on websites.
Source V. Hartikainen
Sort of like the back of a wooden board. Light, subtle, and stylish, just the way we like it!
Source Nikolalek
Prismatic Geometric Pattern Variation 2 With Background
Source GDJ
Not a flat you live inside, like in the UK – but a flat piece of cardboard.
Source Appleshadow
White fabric looking texture with some nice random wave features.
Source Hendrik Lammers
Seamless pattern formed from a tile that can be extracted by selecting the rectangle in Inkscape and using shift-alt-i.
Source Firkin