Mix the dry ingredients – Add the flour, salt and cream of tartar to a medium mixing bowl. Stir to combine.

Boil the liquids – Add the water and oil to a medium saucepan. Bring to a boil and remove from heat.

Mix wet and dry ingredients – Slowly pour the flour mixture into the hot water. Stir constantly until a stiff ball of dough forms (this takes about 3 minutes). Let cool for a minute.

Knead until playdough is soft and pliable – Remove the dough from the saucepan and place on your work center. Knead the dough with your fingers for about 2-3 minutes or until soft and pliable.

Colour the playdough with Thermochromatic Pigments – To make three different colour changing combinations, divide the playdough into three sections. Shape the playdough so it has a little hole in the middle. Into each ball of playdough add a teaspoon of thermochromatic pigment. Carefully knead until the pigment is completely mixed in. Repeat with each of the pigment colours.

Store in an airtight container for up to one month.