In a small bowl, add ¼ teaspoon of borax to ½ cup of warm water. Stir until the borax is dissolved.
In a separate bowl, combine ½ cup of clear school glue with ½ cup of warm water. Add 1 teaspoon of glow powder and stir until everything is evenly combined.
While stirring the glue mixture, slowly pour in the borax solution a little at a time. Continue mixing as the ingredients begin to come together and form slime.
Remove your ball of slime and place it on a clean counter. Knead it with your hands until the excess liquid has been absorbed. If it feels sticky at first, continue kneading for a little longer.
To see the glow-in-the-dark effect, expose the slime to a bright light according to the glow powder directions. Then move it into a dark room and watch it glow!