Enamel Product. The perfect color to give contrast to details and panels on tanks painted with Panzer Grey or any grey tone. Just mix well and use a brush to apply to details, rivets, hatches, etc. and remove excess with a clean brush moist in Enamel Thinner.
The basic technique used to weather any type of model is the wash, a classic technique that is still one of the most used techniques in modelling today.