Magnetic Field Viewing Film 4"x4", Magnetic Flux Display, Magnet Pattern Detector, Scientific Project Teaching, Reusable and Automatic Recovery - Olive

Works great, very cool visualizer.

This is the GOOD stuff, different colors show different field strength. Still doesn't indicate polarity (I've never found one that does), but it's so much better than the dark-green-or-black stuff. This product is laminated which makes it extremely stiff and durable, while the green-or-black is very thin and flexible, and easily damaged. Attached are two photos of the magnetic print bed on my Ender 3 Pro printer. The olive flim easily reveals two small defects where the bed isn't properly magnetized. When I put the green stuff over the same spot, only the smallest subtle hint shows that anything is wrong, it would be easy to miss the defect. Also you can see that the green stuff is already pretty beat up from handling, while the olive remains nearly flawless.

This product has a protective frame, which is better than other products having no frame at all. The frame material is not entirely rigid and it is warped a bit, so the entire assembly is not completely flat, but it is good enough for most applications. I just wish the frame was made out of hard plastic and not two sheets of some hard foam. I would be willing to pay extra for that. The second thing about this product is that it does have a full color spectrum indication, which allows you to see the strength of magnetic field in color, not monochrome, which is really awesome. But, the lookup table for this (which color corresponds to what range of magnetic flux) only exists as a picture on Amazon. I wish the product came with the same picture permanently printed on the frame or at least as some laminated piece of paper. For now, if you order it, you should save the picture from the Amazon page (https://m.media-amazon.com/images/I/61XAvd0ah8S._SL1500_.jpg) and print it out yourself. When this product is no longer listed on Amazon in future, you will be on your own if you don't do that. Also, just like all other similar offerings on Amazon for this category of products, this film is NOT a calibrated measurement instrument, it can only be used for qualitative, not quantitative assessment of the magnetic flux. As long as you remember this, this is a great product to buy.

I purchased this on a whim and have been amazed at how fun it's been to explore magnets with. If you buy this, CHECK OUT A REFRIGERATOR MAGNET! I always thought those cheap magnets were unnoteworthy. It blew my mind to see (and then learn after some googling) that they're a clever arrangement of magnetic field domains known as a Halbach array, which doubles the field on one side (the back) and essentially cancels it on the other (the front). See the striped pattern in my first picture, and check out the Wikipedia articles on Halbach arrays and on refrigerator magnets for more info. For a cool effect, try stacking two fridge magnets and look at the interference patterns as you rotate one while holding the other steady. What caught my attention about this particular viewing film was its multi-color nature based on field strength (many others are monochromatic) and the fact that it "resets" as the fields are taken away, allowing you to see what magnetic fields are currently present and not some mess of the past history. The film appears to change almost immediately at room temperature (not sluggish) as you move a magnet. I don't know how fast it actually is, but I suspect it wouldn't keep up with very rapid changes. This viewing film came with a rigid protective plastic case and a little card showing a rough scale for color versus field strength. I'd take the numbers with a grain of salt, but the color gradient does add some nice qualitative information about the shape and strength of the fields. Colors indicate fields normal (perpendicular) to the plane of the film, and the neutral brownish-yellow color indicates either no appreciable field strength, or fields that are tangential (parallel) to the plane of the film. Although you can't differentiate between North and South, you can easily see where fields are concentrated and where the magnetic field direction changes. Also pictured on the included card is an indication of how the film works. Just guessing, but it looks to me like it might be a thin-film interference effect, where the interference region thickness (which sets the color) depends on how strongly pulled down the internal particles are (which depends on field strength). This would make a great gift for STEM-interested folks (kids and adults alike).

Nice little film, useful for locating magnets inside electronics and for demonstration purposes but requires strong magnets to get the effect you see on the listing pictures which means that the range is also kind of small

There are some cheaper magnetic field viewing films out there. But you get what you pay for. This is a good quality film that does an excellent job for viewing magnetic fields. Overall, this is good value for the money.

This works for the magnets I have but was hoping for reaction further away without having to lay down against magnet to see. I wanted to see how far out the magnetic field extended....maybe I should try putting it against a piece of metal and then slowly progressing the magnet towards the metal until I see a response.

As advertised these viewers give a somewhat easier (Compared to others I've looked at) to interpret analog readout of the field strength with color gradients that are really clear. Does not appear to have any memory/remanance so no degaussing seems to be required. These are mounted on some sturdy cardboard with a 3/4" border all around so the viewer can't come in direct contact with the magnets being viewed, presumably to protect the active underside from damage and it definitely looks like there is also an inactive protective layer on top. This construction may not allow you to directly visualize the field proportions relative to the item being examined as you would with a semi transparent viewer but that is a minor inconvenience far out weighed by the superior aesthetic if the colorful image. I peeled the cardboard off of my 2 units and mounted them to some 10 mil FR4 with double sided PSA... these are suprisingly tough as I had to peel one up to release some air bubbles I had trapped. The underside is jet black. All in all, this is a well crafted bit of magnetic tech.

I had been looking at this magnetic viewing paper for some time as I had an application that would benefit from viewing magnetic field. At first I was put off by the price as $50 is a lot for a 4 inch square of paper but I was also intrigued by the fact that this paper contained colouration to depict different magnetic fields. I decided on this paper, the more expensive option, and hoped I made a good decision. This magnetic viewing paper works great. I am happy that my copy doesn't have the border as shown in the images - mine looks like it is just laminated - which aids in my application of the paper. People that I show this magnetic viewing paper to are amazed on how well it works and how it seems to instantly revert back to its normal state when the magnetic field is removed. Overall, I am happy with this purchase. An option to have this same paper in larger dimensions would be nice - as well as a lower price - but I am currently happy with my purchase.

Diese Folie ist zwar deutlich teurer als die üblichen monochromatischen Magnetflux-Folien, ermöglicht aber tatsächlich eine wesentlich differenziertere und zuverlässig reproduzierbare Darstellung von Magnetfeldern. Außerdem weist diese Folie fast keine Remanenz auf und kann auch in stärkeren Magnetfeldern beliebig oft wiederverwendet werden.

After lot of reading and reluctance, ordered this.. received it after looong time (nearly 3 weeks delay) and was about to even cancel.. All this feel just vanished on receiving the film and running it thru my favo stuff. started with iPhone, where is magically showed the magnetic ring shape,used for charging. and then ran thru my kindle cover to see where the magnets are placed.. and then came the climax. i use copper tube+neodymium magnets to demonstrate Lenz law.. here when i used the film, could nicely visualize the speed of magnet movement inside the tube.. this one visual paid-back the money and time invested :) really loving this. great edu tool. one caution. the size is quite small, like 90 mm x 90 mm. its mentioned in the spec, but somehow i expected a big A4 size sheet.. now trying to understand how the sheet works :))

Justo lo que se ofrece, excelente calidad

Little bit costly, but Good for scientific exploration on megnetic feild visualisation. It need to be very close to magnets / maginetic field to work properly. Finnaly, a good product, as described, fully functional.