Method for the making and decoration of a transparent timepiece component and for affixing decorations on both sides of said component, on a top surface and hollow bottom surface separated by the thickness of said component, characterized in that, in the following order: - in a first station, a first decoration is deposited on a male pattern; - there is moved into a second station, in an injection chamber complementary to said top surface, either said male pattern provided with said first decoration, or respectively said male pattern provided with said first decoration covered with a transparent preform in said first station or in an intermediate station between said first station and said second station, and a first transparent polymerisable material is injected throughout said injection chamber, so as to coat with said first material, either said male pattern provided with said first decoration, or respectively, overmoulding said male pattern provided with said first decoration covered by said preform, so as to obtain a first compound including said top face and including said first decoration on said hollow bottom face; - said first compound injected into said injection chamber is allowed to polymerise; - said first compound is removed from said injection chamber; - a third material or/and a second decoration is deposited in a cavity in a third station where said third material or/and second decoration is held by gravity; - in a third station, said third material or/and second decoration is deposited on said top surface of said first compound by a relative motion between said cavity and said third station in the direction of gravity, so as to obtain a second compound; - in said third station, it is waited until said second compound is handleable; - said second compound is removed from said third station. - in a first station, a first decoration is deposited on a male pattern; - there is moved into a second station, in an injection chamber complementary to said top surface, either said male pattern provided with said first decoration, or respectively said male pattern provided with said first decoration covered with a transparent preform in said first station or in an intermediate station between said first station and said second station, and a first transparent polymerisable material is injected throughout said injection chamber, so as to coat with said first material, either said male pattern provided with said first decoration, or respectively, overmoulding said male pattern provided with said first decoration covered by said preform, so as to obtain a first compound including said top face and including said first decoration on said hollow bottom face; - said first compound injected into said injection chamber is allowed to polymerise; - said first compound is removed from said injection chamber; - a third material or/and a second decoration is deposited in a cavity in a third station where said third material or/and second decoration is held by gravity; - in a third station, said third material or/and second decoration is deposited on said top surface of said first compound by a relative motion between said cavity and said third station in the direction of gravity, so as to obtain a second compound; - in said third station, it is waited until said second compound is handleable; - said second compound is removed from said third station.