Bulut Slime Preparation Kit - How to prepare the Playtoys? Pour the polymer from the large bottle into the mixing bowl. What color you want to make slime on it, color it with the color you want in the coloring packet. Pour the thickener and thickening solution into the bottle on top and mix with a mixing spoon. When the mixture starts to thicken, knead it well, then if you want it to be silver, add the desired color and amount of glitter and complete the mixture.