Cast Iron Skillet Seasoning

My cast iron skillet has been in the family for at least 30 years. Seasoning on the cooking surface is so smooth and dark it looks like black glass. Eggs slide around without oil , and it feels like cheating at cooking. The seasoning is layers of polymerized oil baked into iron at high heat. Each time you cook with fat, the surface gets a little smoother, a little more nonstick. Close to 8 pounds, the pan takes 10 minutes to heat evenly on a gas burner. But once hot, it holds temperature so well that a steak gets a crust in 90 seconds per side without the pan losing heat. Maintaining cast iron is ritual as much as maintenance. Wash with hot water and a chain mail scrubber. Dry on the burner. Rub a thin layer of oil on the surface before storing. Two minutes total, and running your hand across the smooth seasoned surface is satisfying in a way pulling a nonstick pan from the dishwasher isn't. The handle gets screaming hot during cooking, the one genuine design flaw. Leather covers exist, and some people just use a folded towel. What I like is that the pan gets better the more you use it and worse when neglected. That reverses the normal relationship between use and degradation. Most kitchen tools lose value over time. A well-seasoned cast iron skillet is worth more at 30 than at 3, because decades of accumulated seasoning can't be bought or rushed.