How to Make Silly Putty with Borax
To make silly putty with Borax, start by mixing 180 milliliters each of white school glue and hot water. If you want your silly putty to be colorful, add 4-5 drops of your favorite food coloring. In a separate bowl, mix 25.5 grams of Borax with 44 milliliters of hot water. Once the Borax has completely dissolved, transfer about 15 milliliters of the Borax solution to the glue and stir it until the consistency changes to a solid slime. Keep adding 15 milliliters of the Borax solution until your putty becomes stretchy and rubbery. When you're not playing with your putty, keep it in an airtight container so it doesn't dry out.
Pour a 6  fl oz (180 ml) bottle of white school glue into a bowl. Use a glass bowl so your putty won't stick to the sides later. Remove the cap from a 6  fl oz (180 ml) bottle of glue, and empty it into the bowl. Try to get as much of the glue out of the bottle as you can. Use a small popsicle stick to scrape out any glue that might be stuck on the sides of the bottle. Stir the glue with 6  fl oz (180 ml) of hot water. Use the hottest water from your sink to fill a measuring cup. Pour the water into the same bowl as your glue, and stir it with a thick popsicle stick. Continue mixing the glue and water until there aren't any clumps. If you want to adjust how much Silly Putty you make, use equal portions of glue and water. Mix 1 tbsp (25.5 g) of Borax with 3 US tbsp (44 ml) of hot water in a separate bowl. Use the hottest water from your tap so it can dissolve the Borax. Scoop the Borax into the bowl and use a spoon or another popsicle stick to mix the solution together. Make sure the Borax completely dissolves in the water. Borax can be purchased in the cleaning supply section of your local convenience store. Be careful while handling Borax since it may irritate your eyes or skin. Add 1 US tbsp (15 ml) of the Borax solution to the glue and stir. Transfer a little bit of the Borax solution into the bowl with the glue and water. Use your popsicle stick to mix the Borax into the glue. Watch for the consistency to change from a liquid into more of a solid slime. Don't forget to scrape the sides of the bowl so you don't miss mixing any glue. Keep adding 1  tsp (4.9 ml) of the Borax solution until the putty is rubbery. Pour in more of the Borax solution and continue stirring the mixture. As your putty thickens, most of the liquid will disappear from your bowl. Keep mixing and adding the Borax solution until your putty has a stretchy, rubbery texture. If your Silly Putty is runny, keep adding Borax until it starts to thicken up. If your putty gets too solid, you need to start over from the beginning. Store the putty in a resealable container at room temperature. When your putty is finished, keep it in a plastic container with a lid so it doesn't dry out. Leave the putty at room temperature and out of direct sunlight. Whenever you want to play with it, take it out on a clean, hard surface. Avoid playing with your Silly Putty in a carpeted area since it may get stuck in the floor. Add a few drops of food coloring to make your Silly Putty a solid color. Before you add the Borax, put 4-5 drops of food coloring into your glue and stir it together thoroughly. Keep mixing the food coloring into the glue until it turns a pale color. If you want a more vibrant color, add 2-3 more drops at a time and keep mixing the glue. Keep adding food coloring until it's as bright as you want it. If you want a mixed color, such as purple, use even amounts of the colors you're mixing. Mix multiple colors when you first add Borax to make a tie-dye pattern in your putty. After adding 1 US tbsp (15 ml) of the Borax solution to your glue, try putting in 2-3 drops each of different colors your glue. As you stir the mixture together, the colors won't combine and you'll have a multicolored pattern instead. You can also mix together smaller portions of differently colored Silly Putty and knead them together to make them multicolored. Use glitter glue if you want a sparkly putty to play with. Instead of using white school glue, try using 6  fl oz (180 ml) of a glitter glue. Since the consistency of glitter glue is slightly different than school glue, it may take a different amount of Borax for your putty to solidify. Continue mixing the Borax until your putty has a rubbery and stretchy texture. If you don't have glitter glue, you can add any color glitter to putty made with white school glue. 
Pour a 6  fl oz (180 ml) bottle of white school glue into a bowl. Stir the glue with 6  fl oz (180 ml) of hot water. Mix 1 tbsp (25.5 g) of Borax with 3 US tbsp (44 ml) of hot water in a separate bowl. Add 1 US tbsp (15 ml) of the Borax solution to the glue and stir. Keep adding 1  tsp (4.9 ml) of the Borax solution until the putty is rubbery. Store the putty in a resealable container at room temperature. Add a few drops of food coloring to make your Silly Putty a solid color. Mix multiple colors when you first add Borax to make a tie-dye pattern in your putty. Use glitter glue if you want a sparkly putty to play with. 