AK is always the right choice
A great weathering product from AK, as always. Using the slime effect as a base effect and some light colored chalks on top of the moss, and you can create a very realistic build up of moss and lichen
This effect is more pigment heavy than their others, so will lighten like chalk when it dries. It doesn't cut as well with thinners, so I've found good effect stippling it on rather than brush painting