Formed by distorting a JPG from PublicDomainPictures
Source Firkin
Prismatic Geometric Pattern Background No Black
Source GDJ
A seamless striped fabric-like texture colored in a dark reddish brown color.
Source V. Hartikainen
This metal background pattern resembles a metal plate with rivets. Solid rivets on a metal plate.
Source V. Hartikainen
The unit cell for this seamless pattern can be had in Inkscape by selecting the rectangle and using shift+alt+i
Source Firkin
Farmer could be some sort of fabric pattern, with a hint of green.
Source Fabian Schultz
It’s okay to be square! A nice light gray pattern with random squares.
Source Waseem Dahman
Prismatic Curved Diamond Pattern 6 No Background
Source GDJ
Prismatic Groovy Concentric Background 3 No Black
Source GDJ
Remix from a drawing in 'Ostatnie chwile powstania styczniowego', Zygmunt Sulima, 1887.
Source Firkin
Derived from an image that was uploaded to Pixabay by Kaz
Source Firkin
Because I love dark patterns, here is Brushed Alum in a dark coating.
Source Tim Ward
To get the tile this is based on, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Zerro CC tillable texture of stones photographed and made by me. CC0
Source Sojan Janso
Abstract Ellipses Background Grayscale
Source GDJ
There are quite a few grid patterns, but this one is a super tiny grid with some dust for good measure.
Source Dominik Kiss
From a drawing in 'Navigations de Alouys de Cademoste.-La Navigation du Capitaine Pierre Sintre', Alvise da ca da Mosto, 1895.
Source Firkin
A good starting point for a cardboard pattern. This would work well in a variety of colors.
Source Atle Mo
Beautiful dark noise pattern with some dust and grunge.
Source Vincent Klaiber
Here's a camo print with more tan and less green, such as might be used in a desert scenario. This is tileable, so it can be used as a wallpaper or background.
Source Eady
A seamless pattern from a tile made from a jpg on Pixabay. To get the tile select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Recreated from a pattern found in 'Az Osztrák-Magyar Monarchia irásban és képben', 1882. To get the tile this is based on select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Smooth Polaroid pattern with a light blue tint.
Source Daniel Beaton
An abstract pale yellow paper-like background with stains colored in yellow and green.
Source V. Hartikainen