The Faithfull Red Carpenter's Pencils have been designed for general carpentry use and feature a medium hard graphite compound.They can be used to mark almost any material, except for some metals and polished/glazed surfaces, and leave a visible line regardless of the material's grain.FSC-certified wood is used in the manufacture of this product. Wood products with FSC certification undergo a rigorous set of environmental, social, and economic requirements to be considered sustainable and responsibly sourced.