| abstract |
A method for marking an object, wherein the object comprises a material including a functional group and a metal compound or acid that causes an elimination reaction on irradiation with a laser, to form a reaction product of contrasting colour, comprises directing a laser beam on to the areas of the object to be marked. For example, by using a carbohydrate and a metal salt, effective marking can be achieved on the coating of a pill or other edible material. |