With most games offering paid weapon skins these days, naturally I assumed I would have to pay to get weapon skins in Back 4 Blood, for once, a I was delightfully prooven wrong.
Back 4 Blood is the spiritual sucsessor to Left 4 Dead, and while the gameplay mimics much of the classic game, the user interface has evolved somewhat, which I must admit, took some getting used to.
Once you’ve worked your way around the user interface, and realize that you can get to it all from the menu, not just running around Fort Hope, things become a little clearer.
Where to find weapon skins in Back 4 Blood
There are two ways to access the weapon skins and apply them to your arsenal, the first is via Fort Hope, where you will notice a quatermaster.

If you don’t want to keep going to the quatermaster, you can simple access the supply lines from the menu, and select supply lines, where you can then see all the cards you can unlock.

But first, you will need supply points, and to get those you will need to have sucsessfully completed a few missions first, you can see supply points in the top right corner of the menu, as pictured above.
The issue is, most of the time, the Back 4 Blood skins are towards the end of the supply lines, meaning you will need to have enough supply points to unlock any cards that come before it.
As soon as you have enough, continue to the supply lines, and unlock your way to the skin you want, once you have completed a supply line, you will get a new one appear, so you can work towards new cards and skins.

The supply lines also include charictar skins too, so you can focus on unlocking some cool new outfits for your favorite charictars as well as their guns.
Now you know how to unlock weapon skins in Back 4 Blood, get out there and kill some zombies in style.