Mix all the ingredients in the saucepan and heat it slowly, stirring all the time until the mixture thickens and reaches the consistency of cooked mashed potato and leaves the side of the pan. Remove the pan from the heat and allow it to cool. Knead the mixture until it is smooth. It may be necessary to vary the texture slightly but only after one has become proficient in its use. If the amount of oil is sufficient to prevent the mixture from sticking to the skin (which may be rather greasy) the proportion can be reduced.

Both the mixtures described can be coloured at this stage by adding a small drop of the appropriate food colouring and kneading it in. It is much better to add too little dye at first rather than risk spoiling the whole batch.

If using the playdough for wound simulation be aware that red food colouring will give a far better result than cochineal. After each addition of dye and subsequent kneading the resulting shade should be compared with that of the relevant part of the body before adding any more dye.

Storage. If kept in plastic bags the above mix will keep for several days at room temperature but for much longer in a refrigerator. If it is, kept in a freezer it must be allowed enough time in which to thaw completely. The salt in soft tissue prevents it from going mouldy but it will dry out unless it is kept in an air-tight container.