Metal body and wide chisel like the old Sanford markers years ago but no heavy "solvent" smell smells like isopropyl alcohol. having just started using them I can say they are quite slow to dry and I can't comment on the "permanent" claim. But they are probably no less permanent that most ink type "permanent" markers became after the federal safety rules made them eliminate Xylene and / or MEK as ink solvents (liquid bases).