Warhammer Shade Nuln Oil - 18ml Paint Pot

What you're getting

Get yourself a pot of this and you'll see why it's the go-to for bringing out all those fiddly details. It settles into the recesses naturally, giving your miniatures proper depth and shadow without looking overdone. Water-based, so it cleans up easily, and dries to a smooth matt finish that won't catch the light awkwardly.