How to Make Slime Activator

When you’re in your slime-making mom era, it really helps to know how to make slime activator!

I was getting tired of measuring out teaspoons of contact solution or borax every single time we were going to make slime. I didn’t want to spend money on premade slime activators either!

So in order to keep the slime craze cruising in our home without constantly measuring out the ingredients every time, I set out to determine if I could pre-make our slime activator and have it sit shelf stable for awhile.

Guess what?! It worked!

It is completely possible to make slime activator and store it for a bit without any fuss!

Even better, there are TWO glorious ways to make slime activator for glue-based slimes.

No matter which slime activator you make, you’ll want a condiment bottle to store it in. I recommend this pack! These bottles are super convenient for storage and for squeezing when it comes to slime making (and you can use them for making puffy paint too)!

Borax Slime Activator

Borax slime activator is the gold standard!

I’ve been making slime since the 90s.. as in BEFORE it was all the rage! My mom used to make it with my sister and I and the recipe she used was called “gak”. When we made gak (aka slime to this generation) it was always with borax and water!

The slime pros that I’ve seen on YouTube, Reddit, and social media channels often use a borax + water activator like this one! I do think that this activator makes the slime a bit stretchier and is best for some of the more advanced slime recipes.

Another bonus of the borax slime activator? So far I’ve had my activator mixed for just about 2 weeks and the slime we made with it today turned out just fine, so it’s definitely a make-ahead friendly slime activator recipe!

Check out how awesome our last batch of borax slime was – my son was blowing bubbles with it! So stretchy.

You’ll need:

one cup of warmish water
1 teaspoon borax

Combine borax and warm water in glass measuring cup. Stir until borax is dissolved.
Once borax is dissolved, transfer to a labeled squeeze bottle!

When it’s time to use the activator, I recommend adding it one teaspoon at a time until you get the desired consistency!

Contact Solution and Baking Soda Slime Activator

If you don’t want to work with straight borax, this contact solution & baking soda activator is a good one.

The contact solution does contains borax-derived products, but many people are more comfortable with their younger kids working with contact solution and baking soda instead of with pure borax. The only downside is that contact solution is a bit pricier than just borax and water (the other activator – ratios for that below) and I have found that the slime has a tendency to be slightly less stretchy.

As long as the contact solution contains boric acid (which is, yes, derived from borax), you can get the cheapest brand available. At the time of publishing, this brand was $7 for 24oz of contact solution. Not too shabby!

Baking soda is cheap so that’s great! I prefer to buy the huge bags of baking soda at Costco because we use baking soda for slime, for cooking, for cleaning, and even for deodorizing our carpets. If you opt for this, just fill a jar with some of the baking soda and label it and keep in the kitchen so it’s set aside for cooking (and slime making!)!

For one batch of contact solution and baking soda slime activator you’ll need:

1/4 cup baking soda
1/3 cup contact solution (must contain boric acid)

1. In a glass measuring cup, combine 1/4 cup baking soda with 1/3 cup of contact solution containing boric acid.

2. Transfer to a plastic, reusable squeeze bottle! The finished product has a somewhat “milky” appearance:

To use the slime activator, shake bottle well. I recommend a ratio of 1.5 teaspoons per 1/2 cup of glue.

Using Liquid Starch as Slime Activator

Stay-Flo Liquid Starch is a very easy to use slime activator. I don’t iron often enough to even know what I would use this product for aside from slime, but I can say it does make great slime! It’s also very user friendly.

The downside is that it’s a bit pricey.

Typically I recommend using equal parts of glue and liquid starch. The easy measurements also make liquid starch an excellent slime activator for a large group such as summer camp or a party!

How to Store Homemade Slime Activator

Store either of the premixed activators in a squeeze bottle AWAY from young kids and away from your food. I opted to label the bottles clearly: “SLIME ACTIVATOR DO NOT EAT” just to be on the safe side!

I store our slime activator at room temperature. If I ever come across any evidence that storing it cooler in the refrigerator makes a difference, I’ll let you know, but right now – room temperature has been just fine for us.

It’s warm where we live and the house is usually 78-80 degrees. So I’m definitely not keeping the activator cool and it’s been fine!

I suspect it will eventually start to decrease in potency after being stored for a long time, but that is an untested theory! Do you have any experience mixing slime activator and storing it? Share in the comments below!

If you opt for using Stay-Flo liquid starch, just store it in the bottle it comes in!

Have fun squishing and stretching all the amazing slime you’re going to make!

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