Program 30: Galaxy Slime

I thought a perfect science complement to our Summer 2019 Theme of “A Universe of Stories” would be a stellar galaxy slime program!

The trick with slime recipes is trial and error. There are a LOT of people who share a variety of techniques and preferred ingredients online and in books, but most will have slightly different preferences and measurements. Finding the best slime recipe is really finding the best recipe for you. Here is a recipe that I have tried multiple times and used with great success. I based it on a recipe I originally found on the LittleBinsForLittleHands blog online…

Slime Recipe:

  • 1/4 cup Elmers glue (I often use the white glue, but for galaxy or glitter slime, it’s definitely worth the effort to find clear glue for the best results)
  • 1/8 cup water (room temperature)
  • 1/8 cup liquid starch (I have used both Sta-Flo and Linit brands with success)
  • Hand lotion, any brand (trust me – this helps to make the softest, smoothest, loveliest slime!)
  • Gel food coloring (I used the Good Cooking brand gourmet Liqua-gel food coloring which I bought on, using blues, purples, pinks, and black). WARNING: food coloring will stain clothing/carpets, so proceed with caution!
  • Extra fine craft glitter (I purchased some silver and purple glitter on, but I also found extra fine glitter in Michael’s Craft Store)

Additional items:

  • Bowls for mixing ingredients in (I used paper bowls with a coating; you can also use plastic bowls if available)
  • Plastic spoons or craft sticks for mixing
  • Small plastic cups for pre-measured ingredients (I generally prefer to pre-measure ingredients for my scientists to help the flow of the program so that we have more time for enjoying the product of our experiment)
  • Gallon-sized plastic bags to take the slime home in
  • No-stick aluminum foil (I wanted a surface that the kids could play with and the slime wouldn’t stick to)

STEP 1. Pour the glue into a mixing bowl. NOTE: For galaxy slime, we rope together three separate colors of sparkling slime, so you’ll need measure and do this step in three separate bowls. In other words, you’re making three batches of slime that will be colored separately.

STEP 2. Add the water. Stir until combined. Be patient – it may take a few minutes to fully combine.

STEP 3. Not it’s time to add the color to your slime. Because we were making “galaxy” slime, we chose shades of blue, purple, and pink – but in most cases, we made sure that one of our three batches of slime was colored black. You will only need a few drops of the gel food coloring (a little goes a long way).

STEP 4. Time to add the glitter! We used about 1-2 teaspoons of glitter per batch of slime. In other words, you’ll add 1-2 teaspoons of glitter to each of your three bowls. Any color glitter will do, though the extra-fine glitter mixes in particularly well.

STEP 5. Pour in the liquid starch. You can start by stirring with a spoon or craft stick, but pretty quickly you’ll realize that the best way to mix is by using your hands. You need to get in there and do a lot of good squeezing and smooshing, to make sure that all of that liquid starch comes in contact with as much of the glue as possible. In our recipe, the glue contains our polymers, and the starch is what will link all of those polymers together to form our gooey substance. [REMINDER: Food coloring will stain, so if your goo will be traveling around the room, it’s best if you wear protective smocks or protect your floor/table surfaces.] You may find there’s some liquid starch left over in the bottom of the bowl – that’s okay! It just means that all of your glue polymers have already been linked by liquid starch and the rest of the starch is just excess and unnecessary.

TIP: If your slime is not coming together well, try adding a little extra water (only a little at a time!). It’s possible your ratio of ingredients is just a little bit off.

FINAL STEP. I watched a YouTube video where a woman (I’m sorry to say I can’t recall the poster) suggested using a squeeze or two of regular hand lotion onto the slime as a way to make it super soft and supple. And it definitely works! Once you have your slime pretty well combined, just squeeze and little hand lotion on and continue mixing by hand. The results are terrific!

Every single scientist in our group created amazing slime. But what is the science behind the slime?

The borate ions in the slime activators (like our liquid starch) mix with the PVA (polyvinyl acetate) glue and forms this cool stretchy substance. This is called cross-linking! The glue is a polymer and is made up of long, repeating, and identical strands or molecules. These molecules with flow past one another keeping the glue in a liquid state. Until…you add the liquid starch (borate ions) to the mixture, and it then starts to connect these long strands together. They begin to tangle and mix until the substance is less like the liquid you started with and thicker and rubbery like slime! Slime is a polymer.