Have deliberately looking for a brand - decided Cretaceous Product. Unfortunately I have been qualitatively absolutely disappointed. The chalk crumbles and disintegrates already watching. Unfortunately, the delivery was disappointing. The first delivery I received in zebrochenem state. However, the contact with the seller was quick and efficient, so I unhesitatingly received a free replacement. This I would like to emphasize EXTRA. However, the new delivery was unfortunately in a damaged condition. I have it then leave it at that and ordered no more chalk thereof. I thought that I receive at Herlitz quality and appropriate chalk. Unfortunately not. Can not recommend the chalk thus.