I hesitated to purchase these initially based on the price, even on sale. However, a professional artist recommended these and stated that he had his for over 10 years and was able to "refresh" the ones that had dried up very simply. I love these. I'm able to build a value sketch in the french greys and then use colored pencil or watercolor over them. Very eager to try other media also. They blend well and leave no marker streaks on most surfaces (as long as the surface is not too soft).