A bladesmith's apron is a vitally important piece of protective clothing. It has to fit the wearer very well and protect him/her from the sparks, borax splashes and possible flying debris. I made this apron myself and it fits me perfectly. The leathers are all 4 mm thick and in some areas 8 mm thick. It has on the left side a pocket for a spike driver, a hot steel chisel, a smith's square and a vernier caliper.