How to Make Galaxy Slime (Borax Free!)

We are really digging this night sky theme! My kiddos and their classmates are really into sensory exploration right now, and the starry night sky lends itself to so many amazing sensory activities. Today we delved into the world of slime and gak for the first time, and I’m SO glad we did- the kids played with this for hours, and Daddy even joined in the fun! I can’t wait to take this to school with us to see how the kids’ classmates react- I’m betting they’ll love it just as much as we do!

How to Make Galaxy Slime




Since we’ve been studying the night sky at our cooperative preschool, the twins have been talking about it quite a bit at home. They especially love talking about stars, so I showed them some artist’s renderings of the Milky Way galaxy that I found in one of my reference books. As we were admiring the swirls of color, a lightbulb went on in my head, and the idea for Galaxy Slime was born!

Making the slime was pretty easy after I figured out the nuances. Yes, there are nuances to slime making- I’m as surprised as you are ANYWAY, to make our cosmic slime we built upon the tried and true recipe of equal parts Sta-Flo Liquid Starch and Elmer’s Clear School Glue. I wanted our slime to consist of several galaxy colors so I could swirl them into a big spiral for the invitation, so I made smaller batches of black, turquoise, violet, and white/silver using the following proportions (I used the recipe below for each different color):

  • 1 bottle of Elmer’s Clear School Glue (5 oz)
  • 1/2-3/4 cup Sta-Flo Liquid Starch (I found mine at Walmart)
  • Liquid watercolors (several squirts until you get the desired color)
  • Fine glitter in a variety of colors

So here’s the skinny on slime-making…you gotta take it slow. The first time I tried it, I just dumped all the ingredients into a bowl at once and started mixing. After 20 minutes and really sore wrists, it was pretty obvious it wasn’t coming together, so it went into the trash. So I tried again, but this time I followed a different progression. You’ll want to put your glue into a bowl first. Then add your coloring (I used liquid watercolors but I’ve heard that food coloring works, too) and glitter and mix well. THEN you can start adding your starch, but just add it in small increments at a time, stirring well to mix after each one to incorporate your starch fully. After the first couple of additions you’ll need to use your hands to knead the starch in, just like you are making bread dough. Another thing- I know the common wisdom is equal parts starch and glue, but I never needed the entire amount of starch. When I did use the entire 3/4 cup of starch, the dough become more like a gak and wasn’t as stretchy as I wanted. So, just add a little at a time and do a “stretch test” after each increment is kneaded in. Once your slime is the consistency you prefer, STOP!


If you are a regular reader of Twodaloo, you know I love presenting sensory play in fun ways. I decided to spiral our colors together on top of our mirrored tray from Ikea to suggest a sparkly galaxy. I thought it looked pretty inviting, and sure enough, the twins wasted no time jumping right in. My son in particular enjoyed this material- something almost as stretchy and active as he is!



He was completely enthralled with the texture. He wanted to feel it with his hands, his arms, his feet…everything.


Both of the twins were very fascinated with the stretching. And this slime has plenty of streeeeetch!

It’s funny- typically with sensory materials the kids love to add loose parts and/or “guys” (little figures) to engage in some pretend play, but they weren’t interested when it came to the slime. They were just content with exploring it on a purely sensorial level.



Even after all the colors were mixed together, the slime remained beautifully colored and inviting.

I mean, have you ever SEEN a more gorgeous slime bubble? Seriously. Also, “gorgeous slime bubble” is not a phrase I would ever have predicted would be in my lexicon. Just sayin’.


Don’t worry- more on those slime bubbles coming tomorrow. While Will was busy cheesing for photos, Syd was up to her elbows in her own little project, and I can’t wait to share it with you!