A blank for forming a package, the blank comprising: a set of side wall panels comprising a first, second, third and fourth side wall panel (101, 102, 103, 104) arranged consecutively one after another along a longitudinal direction and foldably connected to each other along fold lines extending in a transverse direction, a first bottom panel foldably connected to the first side wall panel along a fold line extending in the longitudinal direction, a second bottom panel foldably connected to the third side wall panel along a fold line extending in the longitudinal direction, wherein the second bottom panel is configured to be positioned beneath the first bottom panel when the blank has been erected into a package, and two opposing side wall portions (110a, 110b), each being foldably connected to a respective transversally extending side of the second bottom panel, and wherein the second bottom panel is configured such that, when the blank is erected into a package, the side wall portions (110a, 110b) are folded relative to the second bottom panel and form together with the respective second and fourth side wall panel two opposing double-walled side walls, characterized in that the first bottom panel comprises two internal, inclined fold lines (107a, 107b), wherein each internal, inclined fold line (107a, 107b) extends along a direction having a major component in the transverse direction, and wherein each internal, inclined fold line (107a, 107b) extends from a transversally extending side (106a, 106b) of the first bottom panel to a free, longitudinally extending side of the first bottom panel, wherein each side wall portion (110a, 110b) comprises an internal, inclined fold line (111a, 111b) extending in a direction having a major component in the longitudinal direction, each internal, inclined fold line (111a, 111b) extending from a longitudinally extending side (110ac, 110bc) of the side wall portion (110a, 110b) opposing the set of side wall panels (101 - 104) to a respective free, transversally extending side (110aa, 110bb) of the respective side wall portion (110a, 110b). a set of side wall panels comprising a first, second, third and fourth side wall panel (101, 102, 103, 104) arranged consecutively one after another along a longitudinal direction and foldably connected to each other along fold lines extending in a transverse direction, a first bottom panel foldably connected to the first side wall panel along a fold line extending in the longitudinal direction, a second bottom panel foldably connected to the third side wall panel along a fold line extending in the longitudinal direction, wherein the second bottom panel is configured to be positioned beneath the first bottom panel when the blank has been erected into a package, and two opposing side wall portions (110a, 110b), each being foldably connected to a respective transversally extending side of the second bottom panel, and wherein the second bottom panel is configured such that, when the blank is erected into a package, the side wall portions (110a, 110b) are folded relative to the second bottom panel and form together with the respective second and fourth side wall panel two opposing double-walled side walls, characterized in that the first bottom panel comprises two internal, inclined fold lines (107a, 107b), wherein each internal, inclined fold line (107a, 107b) extends along a direction having a major component in the transverse direction, and wherein each internal, inclined fold line (107a, 107b) extends from a transversally extending side (106a, 106b) of the first bottom panel to a free, longitudinally extending side of the first bottom panel, wherein each side wall portion (110a, 110b) comprises an internal, inclined fold line (111a, 111b) extending in a direction having a major component in the longitudinal direction, each internal, inclined fold line (111a, 111b) extending from a longitudinally extending side (110ac, 110bc) of the side wall portion (110a, 110b) opposing the set of side wall panels (101 - 104) to a respective free, transversally extending side (110aa, 110bb) of the respective side wall portion (110a, 110b).