Untreated cast iron.
Made by Skeppshult.

In contrast to the following items from Invicta, the cast iron Skeppshult pans are untreated. Food browns well as a result of direct contact with the pan. The disadvantage is that the material is prone to rust. After they have been cast and deburred, the bases of Skeppshult pans are turned, so that they are always completely flat, regardless of whether they are hot or cold.

Maintenance:

Skeppshult pans are baked with a vegetable oil during production - this provides the rust-sensitive cast iron with initial protection.
However, when used on a day-to-day basis, the untreated iron should only be cleaned in hot water, without chemicals or detergents, using a steel brush.
The iron surface should always be dried following cleaning (subsequent drying in a warm oven prevents rust forming in inaccessible places) and should be greased using vegetable oil from time to time.