Abstract: Improvements applied to the case of a smoke bomb.This invention relates to the envelope of a smoke bomb case.It consists, on the one hand, of a traditional wall (1), resistant to the pressure of the smoke bomb constituents (4) when it is the object of the exothermic reaction of the smoke bomb powder, once it has been initiated by an adequate technique. It comprises, on the other hand, at least one area of reduced resistance (3), formed by a relatively fine layer, the said area being covered by a cover (2) of a resistance comparable to the remainder of the traditional wall (1), and which is pierced by a large number of holes (6, 7, and 8).It is characterized by the fact that each hole (6 or 7 or 8) of said cover (2) has a warped form.