These pencils are designed for children to use at home and in school: 33% thicker leads than regular colored pencils; 4mm lead is encased in a standard size barrel. Thicker lead means longer lasting pencils and smooth, rich color lay down. Leads are 20% more break resistant. New formula is stronger and has more pigment for brighter colors and easier blending. Leads will not fall out - SV-bonding means leads are glued the entire length of the barrel and glue is double applied for further reinforcement. 40% easier to sharpen - New radial cutting of wood slats aligns the wood grain for easier sharpening. Ergonomic - Triangular shape is easier to hold and gives better control and pencils will not roll. Eco-Friendly and Non-toxic - Pencils are made from reforested wood preserving natural forests and conforms to ASTM D-4236.