The Souper Cubes Water-Based Paint Marker is perfect for labeling your Souper Cubes tray lids. Simply write directly on the dry lid, wash away with water, and enjoy again and again while your freezer stays organized. Safe and non-toxic, the Souper Cubes Water-Based Paint Marker is ideal for labeling your Souper Cubes tray lids. Simply write directly on the dry lid, then use water to easily wash away for next time. No more trying to remember what you froze or letting food go bad — just better organization and a happier freezer! Its medium 3mm tip size makes this marker great for your arts & crafts projects and use outside the kitchen, too.