The invention relates to a method for manufacture of a product or in completion of a product. A flexible mat (20) is manufactured from an incompletely cured thermo-setting plastic, wherein the mat comprises an article (10) of electrically conductive material. The incompletely cured mat (20) including the article (10) is then formed as a function of a forming tool or to lie against or for contact with a product, whereafter final curing of the mat (20) is executed by supplying electric power to the article (10) or by external heat application or ultraviolet light. The invention also relates to an arrangement and uses.