Each mat is colour coded to prevent cross contamination, easily transfers chopped food from mat to bowl or pan. The 4 mats are Green for Veg, Yellow for Poultry, Red for Meat and Blue for Seafood. Ideal for home or professional catering use, these Mats are really tough and will last a long time for heavy domestic use and almost all catering applications, (e.g. preparing sandwiches and buffet). This set is thicker than average, you can tell the difference because they are not, 'see through', or opaque in comparison. Very Durable in most situations - they will not however withstand a heavy battering from a butcher's meat cleaver!