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 other websites, 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
  • disposable gloves (latex or other)
  • disposable face mask
  • disposable work area (paper plate)

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.

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JessicaS3512 days ago

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.


Cynthia8813 days ago

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?

Laral14 days ago

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.

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!

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

arduinoversusevil made it!20 days ago

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.

mikeasaurus (author)  arduinoversusevil19 days ago

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)

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!)

Pa196314 days ago

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

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!

Will a Home Depot or michaels have the iron oxide? When you call, the kids answering say they don't know what it is
mikeasaurus (author)  Momsgottafindit4 months ago
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!!
micazilla5 months ago

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)  micazilla5 months ago

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.

DadNerd5 months ago

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

JessicaR18 months ago

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

Holy cow. Great project for kids...

davidbarcomb9 months ago

Really cool project. Thanks for sharing this

LP21 year ago
Thank you !
This looks a lot safer than the Kerosene and chemical acid tutorial on you tube.
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)  cbortizfield2 years ago
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.
Laral2 years ago
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:


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!
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.
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 !
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.
"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.)
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.

Magnetic Thinking putty DOES NOT contain magnetised particles.

From: http://www.puttyworld.com:

"When Super Magnetic Thinking Putty is stretched, molded, or shaped, the putty has no magnetic charge and behaves like any other Thinking Putty. However, in the presence of a magnetic field, its magnetic forces begin to align. Suddenly, a truly Super Magnetic Thinking Putty is created that will attract to one magnetic pole and repel from the other."

So it is paramagnetic, NOT ferromagnetic.

So you really do need to read up on magnetism.   (And on Thinking Putty,)

The video shows the behaviour ONLY of free magnetic particles.  
They will not behave like that when randomly mixed into a putty.  
Do the experiment for yourself if you still don't believe me.

Magnetic Thinking Putty will demonstrate NO magnetic behaviour at all without the presence of an actual magnet.
"Magnetic Thinking putty DOES NOT contain magnetised particles."

So you know this for a fact? How do you know?

"From: http://www.puttyworld.com:"

You should link to the exact page where you found this quote.


"When Super Magnetic Thinking Putty is stretched, molded, or shaped, the putty has no magnetic charge and behaves like any other Thinking Putty. However, in the presence of a magnetic field, its magnetic forces begin to align. Suddenly, a truly Super Magnetic Thinking Putty is created that will attract to one magnetic pole and repel from the other."

"So it is paramagnetic, NOT ferromagnetic."

Well, first of all, you need to know the definition of 'paramagnetic'.


"Paramagnetic materials have a small, positive susceptibility to magnetic fields. These materials are slightly attracted by a magnetic field and the material does not retain the magnetic properties when the external field is removed. .. Paramagnetic materials include magnesium, molybdenum, lithium, and tantalum."

So your conclusion is erroneous since the putty DOES retain a considerable amount of residual magnetization after being exposed to a magnetic field. That's why it attracts paperclips in the video. I have some of this putty and it retains a fairly strong magnetic field. It is easily repelled by the opposite pole that it was magnetized with. That rules out paramagnetic material.

"Ferromagnetic materials have a large, positive susceptibility to an external magnetic field. They exhibit a strong attraction to magnetic fields and are able to retain their magnetic properties after the external field has been removed. .. When a magnetizing force is applied, the domains become aligned to produce a strong magnetic field within the part."

OK but the residual field after the magnet is removed is negligible. Again, from my personal experience, this DIY putty does not retain any noticeable magnetic field after being in contact with even a very strong neodymium magnet. It exhibits no magnetic polarization. So the only possible conclusion is that there is MAGNETIC, as in magnetized, material in this putty. That's the only way it could exhibit the properties it has.

See Crazy Aarons' comment:


"The first time I added this black pigment to our putty, I noticed, accidentally, that it was attracted to magnets. That is what gave me the idea to create our magnetic putty. The stuff we sell as Strange Attractor or Quicksilver has a few secret ingredients that add considerably more kick.

For example, with Iron Oxide, you can't get the putty to pick up paperclips or repel a magnet when you switch the poles."

The secret ingredient has to be magnet powder.

"So you really do need to read up on magnetism.   (And on Thinking Putty,)"

Before you go making challenging statements like this, in such a disrespectful manner, and posting information that is erroneous, you really should do some online research and then take a course or two in Electricity and Magnetism,  so you know what you are talking about. You clearly haven't done that and have virtually no understanding of the topic.

"The video shows the behaviour ONLY of free magnetic particles. 
They will not behave like that when randomly mixed into a putty. 
Do the experiment for yourself if you still don't believe me."

They behave exactly the same way though the movement of the particles is slowed due to the high viscosity of the putty. And, as I have stated numerous times, I HAVE done the experiment myself. I suggest that, after you do your homework on the subject at hand, you then purchase some of the putty and perform your own experiments. You really can't go telling someone who HAS done the experiments to go do the experiments when they already have and YOU haven't. That's illogical.

"Magnetic Thinking Putty will demonstrate NO magnetic behaviour at all without the presence of an actual magnet."

Actually, AFTER coming in contact with a magnet, the putty is magnetized for a while and behaves like a regular magnet. Again, that is why it can attract paperclips and be repelled by a magnet.
you could have conductivity as long as the voltage were high enough to arc from particle to particle within the putty. even air becomes conductive at a high enough voltage, its just a matter of how much voltage you would need to make that jump. Unfortunately the only magnetism I was ever good with in school was electromagnetism. What can I say? I'm a computer geek, not a physics major.
You're talking about enough voltage to arc between tiny conductive particles surrounded by a non-conductive medium. Odds are you would get an arc between the terminals without the modified putty. Either way, I wouldn't want to be anywhere near it when you turn the juice on.
Any thing above 3.5 vdc will jump if allowed to. And with enough iron oxide powder it will work with just 1 vdc applied.

Electricity is nothing more then a theory and I dare you say differently.
As an electrician I have seen electricity do some really strange things that cannot be explained by theory alone.

And remember VOLTS do not kill AMPs do.

P.S. I already tried and it will pass 1 vdc. Pretty cool..
Yeah, I can only think that arcing within the putty would put bits of it all over the room.

That could be fun too, though.
A car engine spark plug takes about 20,000 Volts to reliably cross a (fairly clear) air gap of about 1/25 of an inch (1mm).

For BlackFang's putty to conduct, the voltage would need to be sufficient high to cross the sum of all the gaps between the particles, impeded by the insulation of the putty.  Do the math if you want to !

BlackFang, I advise a welder's mask at the very least !

I shall be with psibbald, on the other side of the (steel) door.
Steel be buggered. Glass is an electrical insulator and we could watch the fun.
Can we compromise: Transparent Aluminium ? I've always wanted to try some. It is bulletproof, but I'm not sure about it's conductivity.
I agree it is counter intuitive, but at work I have made use of electrically conductive paints made from silver particles or graphite particles dispersed in a polymeric binder and solvent. There is even a company making a conductive printing ink based on finely divided copper particles. I guess you can get a sufficiently continuous path of connecting particles if they are small enough and of a very high concentration. I would imagine though that at this level of concentration the VE properties of the silly-putty would be lost.
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