Why you NEED this Test Grid - Every piece of stainless steel is different. Different finishes, coatings and hardness levels can drastically change how your F1 Ultra fiber laser engraves. Running a test grid on every single piece of new material ensures you get crisp, permanent marks without wasting material. More importantly keeping these grids builds you a personal "laser recipe book" you can refer to later. The pros do it and you should too because guessing is expensive.