STAEDTLER Mars Lumograph Aquarell Pencils are premium quality, water-soluble graphite pencils with a special lead formulation that make them break-resistant. They are great for shading and adding interest to sketching. These graphite drawing pencils are made so they can be mixed with water to create stunning watercolour effects. These artist quality pencils are made from wood from certified, sustainably managed forests with 3.6mm (4B & 6B) and 4.5mm (8B) diameter break-resistant leads.