The quality is good the Cretaceous. However, you really have to "carefully" write on the wall, so that these pieces of chalk not break a little. The chalk sticks are not very thick and not covered with paper. Therefore, of course, not as stable as normal white chalk. This, however, gives the advantage that finer images can be painted or thinner geschreiben.
My delivery was 100% OK, that it was broken a single piece.
Conclusion: I am happy with the product. From me therefore a buy recommendation.