Metallic gold pigment is ideal for handmade soap. You can add the colour to the melted base and mix it in to colour the whole bar of soap, or you can achieve interesting effects by colouring only part of the soap base. If you are using a base for making creamy soap, there is no need to melt it. Add 1-4ml per 100g of soap base, depending on the depth of colour you want to achieve.