A set of panels including a first panel and a second panel configured to assume a locked state in which a first main plane of the first panel is arranged at an angle of between 30° and 150° relative to a second main plane of the second panel. A separate tongue arranged in an insertion groove of a groove is configured to cooperate with a tongue groove provided in an edge section of the second panel for locking the first and second panels to each other in a first direction perpendicular to the first main plane, and the edge section is configured to cooperate with the groove for locking the first and second panels to each other in a second direction parallel to the first main plane. A bottom portion of the groove includes an elevated portion arranged at least in an outer section of the groove along the second direction, wherein an area of the elevated portion is at least 3% of an area of a rectangular bounded region extending along boundaries of the bottom portion.