Depending on the ingredients you have used it will take about 2-4 tablespoons of Borax solution to make slime - but this does vary, so take your time and add it slowly. Make sure you mix well between adding each small amount of activator. It takes a short time for it to work, so you want to make sure it has fully reacted before adding more. Here's what this recipe used: ¾ cups water. ¾ tsp borax. 1 ½ cup glue and ¾ cup water. The mixing part for this recipe is very easy. Simply mix the water and borax together in one bowl. Then mix the glue and water together in another bowl. You can add food coloring to either bowl. After this, mix the contents of the two bowls together. Add 1/2 cup Elmer's School Glue to the mixing bowl. Add a teaspoon of baking soda to the mixing bowl. Stir everything together with a spatula or large spoon. Add a tablespoon of contact solution (15 ml) to the bowl. Stir it all together! Add the baking soda: Add the baking soda to the glue mixture and stir until smooth. Add the contact lens solution: Pour in 2 tablespoons of the contact lens solution and stir slowly. The mixture should begin to harden, becoming stringy. Mix until a ball forms: Continue mixing slowly until a ball of slime forms. Instructions: Squeeze 4 oz. of glue into the glass bowl. For sparkly slime, add glitter, or use glitter glue! For nighttime slimy fun, try glow-in-the-dark glue. Elmer's makes a whole line of slime products! Mix 1/2 TBSP baking soda into the glue. Add a few drops of food coloring and stir all three ingredients altogether. Gradually add the slime activator ~ 1 teaspoon at a time (if you make your own slime activator, mix 1 cup of warm water with 1 tsp of borax). 1 Cup Water, 1 tsp Borax Mix it together and continue add activator until it starts to pull away from the edges. Then stretch it with your hands. Add in more shaving cream a little at a time. How to Make Slime Activator with Borax The key to the best activator for slime is borax. It's used primarily as a laundry detergent, but it lives in my craft room since I have so many crafts that use borax . Fill a bowl or measuring cup with 1 cup of warm water. Then add in 1 tsp of borax. Mix until all of the borax is dissolved. Add the bicarbonate of soda and mix well. 2. Add a drop or two of your chosen gel food colouring. Less colouring gives a pastel colour; the more you add, the brighter the colour. Mix until well incorporated. 3. Add the contact lens solution and mix. The slime will begin to form, going stringy before coming away clean from the bowl into a ball. Step 3 Squeeze out a blob of PVA glue onto the plate next to the toothpaste. DO NOT squirt the glue on top of the toothpaste as it can cause the slime to become watery or even be lumpy - urgh!!! The quantity of glue should be just slightly smaller than the blob of toothpaste used. Step 4 Start mixing the glue into the toothpaste little by little. STEP 2: Add 1/2 cup of water to the glue and mix well. STEP 3: Add several tablespoons of your beach or play sand and mix into the glue/water mixture. STEP 4: Measure and add 1/4 cup of liquid starch to your bowl and stir. Slime will begin to form immediately. You should keep stirring until slime pulls away nicely from sides and bottom of bowl.