Agglo-marble is a material consisting of 95% natural marble aggregate and 5% polyester resin used as a binder. It comes in a full range of colors, and its uniformity of color allows it to be used on large surfaces. In addition, agglo-marble makes it possible to create and duplicate patterns and colors, which is one of its basic advantages in interior design and decoration. Internal windowsills made of marble conglomerate are designed for installation with PVC, wooden, and aluminum windows. Due to the differences in the structure of the material, fine-grained conglomerates compared to coarse-grained ones have three times lower absorption of water, twice as much resistance to bending, and approx. 30% higher compressive strength. Physical and mechanical properties of agglo-marble often outweigh those of the natural stone.