What is slime? It's a gooey, squishy, pliable substance usually made from a mixture of nontoxic craft glue like Clear Gel Tacky Glue, water and borax (a common ingredient in household laundry and cleaning products) or contact lens solution. Slime can be colored with food coloring, nontoxic paint and glitter. Use this slime recipe on how to make slime with Original Tacky Glue. Slime should always be made while under the supervision of an adult and it is recommended that children should be of at least school age before making. Store slime in a plastic container or re-sealable plastic bag to keep it fresh longer. Always wash hands before and after playing with slime, and immediately discard if it starts to change color or odor.