Magnetic Viewing Film (3 x 4 inches)

This is really good for visualizing magnetic forces, it also lets you see where magnets are hidden in a part.

Did the job exactly as expected. Wanted to determine if my bass pickups were true humbuckers.After all the commotion from FMIC/Gretsch about the pups on the G2220 bass which was supposed to be humbuckers I wanted to make sure my Ibanez Artcore bass was as advertised/specified.

Who says magnetic fields have to be invisible? This viewing film begs to differ. I've seen these used in videos and demos, and just had to try it out for myself.It really does what it says--you put this over a magnet, and it changes colors based on the orientation of the magnetic field (Black if it's perpendicular to the surface, green if it's parallel--it won't tell you direction though). In fact, it's a great way to visualize magnetic flux if you wrap it around a magnet. Other cool experiments include viewing the magnetic poles in a Halbach array (Fun fact--some fridge magnets use this!) and testing the magnetization of ferrous objects.They're also useful for showing the magnets hidden in everyday objects, such as earbuds, hard drives, and laptop screens. All you have to do is wave it over your object, and watch the film darken around the magnet.One quirk about films of this type is that they don't "reset" when you pull it away from your magnet. Don't worry--it's reusable, but you'll have to scrub it with a magnet to "erase" the lines. A large sheet magnet (like the thin fridge magnets you get from souvenir shops) seems to work well for this.The film is a little pricey, however. I suppose there's not much of a market for these outside of physics and engineering. They're made up of thousands of microscopic oil-filled bubbles, which probably involves some specialized manufacturing process. Nevertheless, it came nicely-packaged in a stiff cardboard pouch, complete with instructions.Despite the price, this is a neat tool that has both educational and practical value.

Many modern camshafts have magnetic rings for determining camshaft position. If those magnetic fields degrade or get distorted, your engine won't run properly. This is a cheap, effective way to "see" the magnets of those rings. Check YT for more info.

Works as expected and described

Perfect

Works great around neodymium magnets as a demo, but it is not sensitive enough to react to a hunk of magnetite I have. Mixed bag. Also was not cut very neatly, so don't expect it to be quite as nice as pictured.

Not sure how this thing works, but it really does. I needed to test the position of my engine cam reluctantly rings to see if they were intact and hadn’t slipped