Enjoy low-odor markers that are ACMI certified and conform to ASTM D4236, meaning they’ve been independently tested and meet strict safety standards for art materials Water resistant and wear resistant ink dries quickly when applied and is designed to endure harsh conditions Jumbo marker features a wide barrel and a 5/8" chisel tip so that your lines can be thin or extra wide Permanent markers won't dry out for up to half an hour without a cap Write smoothly on almost any surface with these red markers including cardboard boxes, PVC pipes, concrete walls, plastic bins and more