Introduction: Magnetic Silly Putty

Picture of Magnetic Silly Putty

Thinking Putty (also known as Silly Putty) is a silicone polymer children's toy. Silly putty is fun because it has some unique properties: it is viscoelastic, meaning it can be stretched and shaped and mashed back together again; and as its apparent viscosity increases directly with respect to the amount of force applied (read: it can be torn or shattered with impact). Silly putty is a non-Newtonian viscoelastic polymer, better characterized as a dilatant fluid. Also, it bounces.

Ok, enough science. I'm sure we've all played with Thinking Putty in our youth, but how about magnetic silly putty?

By adding a ferrous component to an already wacky toy we can keep all characteristics of the original putty, but now have the additional dimension of magnetism! I've seen magnetic thinking putty for sale on otherwebsites, but I'll show you how you can make your own for a fraction of the price and in about 20 minutes.

Enough talk, let's make some magnetic putty!

Step 1: Tools + Materials

Picture of Tools + Materials

The secret ingredient that makes the putty magnetic is an iron oxide powder, which is ferric (magnetic). Ferric iron oxide is a fine powder used as black pigment and can be found at art stores. If your local artist supply store doesn't carry it, you can always purchase it black iron oxide powderonline.

Step 2: Prepare Putty

Picture of Prepare Putty

Start by clearing a space to work, make sure it is well ventilated. Iron oxide powder is very fine and inhaling it is probably not such a good idea. Put on your gloves and face mask before you begin.

Open the thinking putty and remove from the container. Work the putty in your hands a little to warm it up, then stretch it out like a sheet and lay it on your disposable work surface (sheet of paper or paper plate).

Step 3: Add Iron Oxide

Picture of Add Iron Oxide

Thinking Putty comes in different sizes, depending on where you purchase it. I found mine in a local toy shop, it comes in an egg-shaped container and is about 24 grams (0.8 oz).

For this size, I used about a tablespoon of iron oxide, you may require more or less depending on your putty size and amount of magnitism desired.

Carefully spoon the iron oxide into centre of putty sheet, then close lid on iron oxide powder to reduce excess iron dust escaping.

Step 4: Work It

Picture of Work It

Gently fold edges of putty sheet into centre and work the powder into the putty. Go slow, the powder produces lots of dust.

After a minute of massaging the putty it will lose it's colour and begin to look black as pitch. Keep massaging putty for about 3-4 minutes.

Step 5: Experiment and Have Fun!

Picture of Experiment and Have Fun!
That's it, you're done! Grab your magnet and start experimenting with your new magnetic putty.

You can stretch out a strand and make it follow your magnet, you can polarize your putty to work as a magnet itself, and then there's the classic of placing the magnet directly on the putty and watching it envelop the magnet. There's plenty of fun to be had, check out the video I made with some of the fun you can do.

Some frames have been sped-up to illustrate magnetic properties.
Of course, aside from being magnetic your putty still retains all the properties of the original Silly Putty.

Putty has been known to leave a residue on some surfaces, even more so with the iron oxide powder. Use caution when playing with your magnetic putty.
If you get magnetic putty stuck to fabric you can try placing the magnet on top of the fabric and the putty may work it's way out (wait 24 hours). Alternatively you can apply rubbing alcohol to area and work out the putty, try a concealed test-area first. WD-40 may also work. If all else fails, take the fabric to the dry cleaners and tell them it's a silicone-based stain.

What are you waiting for? Get going and make your own magnetic putty!
Place a picture or video of your version of magnetic putty in the comments below and earn yourself a digital patch and a 3-month Pro Membership to!

Have fun!


Momsgottafindit (author)2015-04-16

Will a Home Depot or michaels have the iron oxide? When you call, the kids answering say they don't know what it is

Yes, cement section, black coloring for cement is iron oxide powder.

Thank you so much, I (unfortunately) figured that out after driving back n forth in rush hour traffic lol.. I guess on to new idea for project and try that when not in time crunch..THANKS AGAIN!!

Bverysharp (author)2017-08-30

You can get black iron oxide at any hardware store, in the cement colorant section.

The black one is iron oxide, and it's quite cheap.

Sallybinzwigs (author)2015-08-22

I'm sorry to be a party pooper but there are some very serious health hazards to be concerned about when handling black oxide of iron! Please check out this health hazard warning before trying this experiment and use a breathing mask if you do plan on doing this for sure!!

It can even change your eye colour after some people have been exposed!

Follow this link for more info on the health hazards of using black iron oxide.

You realize the link you sent is for Iron Oxide, which is just plain ole rust, created naturally. Granted this is the same name (contains similar chemical composition), it is also a refined product which is produced artificially for the purpose of being a pigment.

Still, like any fine particulate, not good to be breathing in without proper respirator/mask etc.

Mark 42 (author)ccopyrites19862017-08-29

"Still, like any fine particulate, not good to be breathing in..."

Have you seen the "Will it Blend" series on YouTube?

Laral (author)Sallybinzwigs2015-10-18

My eyes changed from brown to brown…

Greywolfg (author)Laral2016-04-08


AidanK4 (author)Sallybinzwigs2015-09-04

But it's only the powder, right? Say, for ferromagnetic fluid, it's going to be suspended in a bottle of liquid. And with this silly putty, it's mixed in. Plus, why would you ever make repeated contact with the powder in the first place? It has no use by itself. You only need it to make whatever, and beyond that point it's safe. At least that's my hope. I don't want to order a big jar and mix it in only to find that I'm gonna up and die from handling the stupid stuff. :(

Mark 42 (author)2017-08-29

I wonder if using an old style ferro magnet and sanding it into powder would be stronger than iron oxide. A belt sander could sand a few magnets into power fairly quickly.

cmencke0891 (author)2017-02-27


super_me (author)2016-12-28

This is actually a product that you can buy - it's called Crazy Aaron's Thinking Putty, and they also have a magnetic version of it. Just saying... Crazy Aaron have a whole lot of cool Thinking Putty so check it out on Vat 19 or on their website.

PS: this is not a promotion

mikeasaurus (author)super_me2017-01-03

I made this project before magnetic putty was commercially available, the way it is now.

Also, my buy when you can make? :)

super_me (author)mikeasaurus2017-01-06

Sorry, didn't know that you made it before it was available commercially. Anyway, I do like the idea, and I'd like to try it. Btw is the toner thing easy to buy or do you have to buy it from somewhere online?

mikeasaurus (author)super_me2017-01-06
MichelleB186 (author)2016-04-24

I really do love this, but it's just not safe for little kids in my mind not for a whole bunch at a party anyways! I think for an at home project with your kids yes because you can just make it when there in bed and let them play with it the next day! but there is also other ways to make this which are safer! but still thanks for the post it's great!

Laral (author)2015-08-20

I also made two fluorescent colors of putty that glow nicely under black light. I rolled the putty into a ball and set it on top of a plastic container with a powerful cylinder magnet at the top and let it sit for hours until a nice 'bloom' developed. The third one is a ball placed directly on top of a 2" square neodymium magnet.

mikeasaurus (author)Laral2015-10-18

These look amazing! Mind sharing your process for making them luminescent? It's really cool.

Thanks for sharing your pictures, enjoy the Pro Membership!

Laral (author)mikeasaurus2015-10-18

The colors are fluorescent and need a black light to make the glow. I tried using phosphorescent 'glow' powder but with little success. I just add LOTS of fluorescent pigment mixed with a fine gray iron oxide to CLEAR putty from Aaron. I am thinking of doing an Instructable on it. BTW thank you for another 3 months PRO membership. I appreciate it.

Ruby2005 (author)2015-10-18


Cynthia88 (author)2015-08-21

Sooooo, little kid friendly? I'd love to show this to my preschooler and kindergartener, but considering the contents, is that just a horrible idea?

Fishyfish123 (author)2014-05-18

I once got some putty stuck on my pants and I washed it and it but it stayed in. Them I use some goo-gone. It it orange stuff you can buy and it is a miracle. If you ever get any goo stuck on something, no matter what the bottle says, USE IT!

AustynSN (author)Fishyfish1232015-08-20

Goo-gone is awesome. Also good for erasing permanent marker.

arduinoversusevil made it! (author)2015-08-14

I made it, but with less viscous silly putty. I had to add Dimethecone to allow the silly putty to flow better. Also, I used cast iron filings from my metal lathe.

Ha, I had just watched your YouTube video before seeing this comment!

I actually tried this project initially using iron from steel wool, since it was already very fine. The results weren't great. I'm glad to see you had much more success.

I saw your video about kinetic sand and was wondering when you'd tell us your hobby store solution to dimethicone. Watching your silly putty video was revealing, I'd never had thought that RC car shock oil would be the replacement.

Your channel is very entertaining and I never miss an episode. Stay awesome!
(also, for sharing a picture of your magnetic putty here you've got a free Pro Membership)

Laral (author)mikeasaurus2015-08-20

I mentioned using silicone oil over a year ago, a few comments down

and even provided a before and after video about it

DIY Magnetic Putty 'Swallows' 1/2" Cube Magnet in 32.5 Seconds!

Dimethicone is the pure silicone oil that is in RC shock oil and is way cheaper. I bought a half pint of it for under $10 on eBay.

Cheers man, thanks! Because it's a lot less viscous I'm hoping to have success manipulating it with some sequenced electromagnets... Stay tuned! I'll link back to your instructable too. (reach around FTW!)

Pa1963 (author)2015-08-20

I'm gonna mix it with some oobleck and see what happens.

lovethebackwoods (author)2015-08-20

While I was Outside this summer (Outside of Alaska, that is) I bought a small tool in a big box home improvement store. It looks like a small plastic blue "thing." However, one can magnetize or demagnetize screwdrivers, knives, etc. by drawing them several times through one of the two slots. I found it fascinating. (And no, I will not put the magnetic putty that I will surely make soon into the tool just to see - whatever!) Pictures to follow... Thanks for this most interesting project. Very well explained and illustrated!

micazilla (author)2015-03-24

Is this safe/easy enough for a 7 year old to take to school and combine the 2 there? He has an assignment to make a magnetic toy.

mikeasaurus (author)micazilla2015-03-24

It's messy. Though the iron oxide won't stain once it's in the putty, if any gets spilled before mixing it's going to stain.

Would not recommend without supervision.

DadNerd (author)2015-03-19

Really cool. I'll have to do this with my son when he gets a little older!

JessicaR1 (author)2014-12-19

this just makes me smile all over. A great, fun, STEM project I think.

Curated Quotes (author)2014-11-29

Holy cow. Great project for kids...

davidbarcomb (author)2014-11-25

Really cool project. Thanks for sharing this

LP2 (author)2013-11-23

Thank you !
This looks a lot safer than the Kerosene and chemical acid tutorial on you tube.

cbortizfield (author)2013-09-02

i have a question is the stuff you get off the ground when you place a magnet in the dirt the same as Ferric iron oxide and even if it isn't, if you were to collect enough of it and mix it with the putty would it work the same? (possabily with out turning it black?)

mikeasaurus (author)cbortizfield2013-09-03

When you sweep a magnet over dirt you are likely picking up rust, which is exactly what iron oxide is. This should work, but a powdered iron oxide will produce more favourable results, as the consistancy will be uniform, and you won't have any potential sharp bits from an unknown substance that you collected from the ground.

mikeasaurus (author)2013-08-26

Thanks for sharing your version, the pictures look amazing!
Enjoy the digital patch and the 3-month Pro Membership

Laral (author)mikeasaurus2013-08-26

Wow, thanks! Did you also see the video? I tried to delete the above post and redo it with the video embedded this time. See below.

Penolopy Bulnick (author)2013-08-26

That is uber sweet looking!

Laral (author)2013-08-26
I made a batch of this with some putty and some black iron oxide (Fe3O4) I had on hand and it is pretty cool. I left a blob of it on a glass tabletop with a couple of strong neodymium magnets under the glass and it morphed into some kind of alien-looking black magnetic 'fungus'. :)

I thought it would just flatten out, but it turns out that the iron oxide particles try to align themselves to the magnetic field, impeded by a viscous fluid, so they form random "regions". Pretty neat.

Some commercial putty I have behaves differently.

It has magnetized powder in it so the particles are able to align themselves more uniformly despite the viscous fluid. Interesting.

BTW the putty I made is too stiff, so I later added some silicone oil to it to soften it. I posted on this in the other Instructable:

Here's a video with a side-by-side comparison:

BlackFang171 (author)2011-06-10

Wouldn't it be completely amazing to crush neodymium magnets into a powder, and mix the silly putty with a combination of that and graphite? You should come out with a conductive and highly magnetic putty.

Real world uses for a substance like this...GO!

psibbald (author)BlackFang1712011-06-10

Be careful. Neodymium magnets are extremely brittle which means they are likely to shatter violently if you try crushing them. The pieces also have very sharp edges (I know that from experience!). To make matters worse, the powder produced is highly reductive and can oxidise so rapidly that it ignites.

You also need to bear in mind that if the attraction between the magnetic particles and the surface you put the putty on is greater than the adhesive properties of the putty itself then the particles will be left behind and you'll eventually end up with magnetic powder all over your house.

As for they idea of the putty becoming conductive with the addition of conductive powders, there would need to be a continuous path of conductive particles from one terminal to the other. I doubt that there would be enough putty in such a mixture to retain its putty properties.

Sorry to be such a downer.

ElectroFrank (author)psibbald2011-06-10

Downer number two: It won't work anyway.

A magnet is only magnetic because all the microscopic magnetic domains are all lined up the same way.

If you crushed a magnet into powder and mixed it in, there would be no overall magnetic effect, because all the magnetic domains would be randomly aligned, and would cancel each other out.

The only effective "magnetic" powder you can mix in must be "paramagnetic", that is, attracted by magnet, but not a magnet itself.

(Yoda voice:)  No sorry !  In science class, more attention you must pay, young Smilewalker !

Laral (author)ElectroFrank2013-08-23

Absolutely wrong! Magnetic powder is polarized by a magnet. Inside of putty the polarization keeps for quite a while. This is NOT the case with just iron oxide or filings.

ElectroFrank (author)Laral2013-08-24

"Magnetic powder" ? What magnetic powder ?
The powder of a crushed magnet will behave as I have said.

If you magnetised a ferromagnetic powder _after_ mixing it into the putty, it would create a magnet, but the magnetic domains would start cancelling each other out as soon as the putty was re-moulded into a different shape.

May I suggest you read up on "Magnetism" on Wikipedia ?
And do the experiment to test your theory ?

(Repeat Yoda comment.)

Laral (author)ElectroFrank2013-08-24
No need to read up on magnetism. I did that in my E&M course in college. I am talking from personal experience. The magnetic Thinking Putty contains powdered magnetized particles and behaves as I have already described. Watch this video for a dramatic demonstration of the difference between FERROmagnetic powder and MAGNET(ic) powder. Really awesome difference. I assume this is what TP contains.

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Bio: I'm Mike and I make crazy things at Instructables HQ in San Francisco. Follow me and try a few of my projects for yourself!
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