An interesting dark spotted pattern at an angle.
Source Hendrik Lammers
Embossed lines and squares with subtle highlights.
Source Alex Parker
Seamless pattern the tile for which can be had by using shift-alt-I on the selected rectangle in Inkscape.
Source Firkin
Remixed from a drawing in 'Hungary. A guide book. By several authors', 1890.
Source Firkin
Based on several public domain drawings on Wikimedia Commons. This was formed from a rectangular tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Prismatic Hypnotic Pattern 2 No Background
Source GDJ
The tile this fill pattern is based on can be had by using shift+alt+i on the rectangle.
Source Firkin
Might not be super subtle, but quite original in its form.
Source Alex Smith
Abstract Geometric Monochrome Pattern Prismatic No Background
Source GDJ
A pattern formed from a squared tile. The tile can be accessed in Inkscape by selecting the rectangle and using shift-alt-i.
Source Firkin
Retro Circles Background 8 No Black
Source GDJ
Prismatic Groovy Concentric Background 2
Source GDJ
Spice up your next school project with this icon background.
Source Swetha
Prismatic Groovy Concentric Background 2 No Black
Source GDJ
An abstract Background pattern of purple twisty patterns.
Source TikiGiki
Because I love dark patterns, here is Brushed Alum in a dark coating.
Source Tim Ward
Very dark pattern with some noise and 45-degree lines.
Source Stefan Aleksić
The image depicts polka dot seamless pattern.
Source Yamachem
Sort of like the back of a wooden board. Light, subtle, and stylish, just the way we like it!
Source Nikolalek
The image depicts an edo-era pattern called "same-komon" or "鮫小紋"which looks like a shark skin.The "same" in Japanese means shark in English.
Source Yamachem
Derived from a corner decoration itself found as a jpg on Pixabay.
Source Firkin