Everyone enjoys making slime!!! Can be colored using food dyes. This class slime kit contains: 1 liter of colorless 4% polyvinyl alcohol, enough 4% sodium tetraborate solution to cross-link with it. A food preservative has been added to avoid the growth of unwanted creatures. Investigate a cross-linked polymer. If pulled slowly, it flows; if pulled quickly, it breaks; and if rolled into a ball, it bounces. Enough for more than 60 students to make a 1/2 ounce portion (~15 cc).