The first pattern on here using opacity. Try it on a site with a colored background, or even using mixed colors.
Source Nathan Spady
All good things come in threes, so I give you the third in my little concrete wall series.
Source Atle Mo
A free web background image with a seamless concrete-like texture and an Indian-red color.
Source V. Hartikainen
I love cream! 50x50px and lovely in all the good ways.
Source Thomas Myrman
It has waves, so make sure you don’t get sea sickness.
Source CoolPatterns
A beautiful dark wood pattern, superbly tiled.
Source Omar Alvarado
Remixed from a drawing in 'Chambéry à la fin du XIVe siècle', Timoleon Chapperon, 1863.
Source Firkin
To get the tile this is based on, select the rectangle in Inkscape and use shift-alt-i.
Source Firkin
Sharp pixel pattern looking like some sort of fabric.
Source Dmitry
Love the style on this one, very fresh. Diagonal diamond pattern. Get it?
Source INS
From a tile that can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
Everyone needs some stardust. Sprinkle it on your next project.
Source Atle Mo
Sometimes simple really is what you need, and this could fit you well.
Source Factorio.us Collective
Remixed from a design seen on Pixabay. The basic tile can be had by selecting the rectangle in Inkscape and using shift+alt+i.
Source Firkin
A car pattern?! Can it be subtle? I say yes!
Source Radosław Rzepecki
A pattern derived from part of a fractal rendering in Paint.net.
Source Firkin
A seamless pattern formed from a sports car on clker.com. To get the tile, select the rectangle in Inkscape and use shift+alt+i.
Source Firkin
Remixed from a drawing in 'The Canadian horticulturist', 1892
Source Firkin
A pale orange background pattern with glossy groove stripes.
Source V. Hartikainen