Skin grafts may take on any surface that is sufficiently vascular, but they take best on granulation tissue which is in a favourable state for accepting them. This is why it is often best to wait 3 days for granulations to form on a wound, ulcer, or burn before you graft it. Here are the signs which tell you whether granulations will accept a graft or not. If there are several unfavourable signs, prepare the granulations first.