I'm a Lab Tech by trade and Parafilm is a staple in the Lab for sealing tubes and other things containing liquid and other contents.

At home I've found many other uses besides sealing things, including holding things together, stopping leaky hose connections, waterproofing connections, keeping bananas fresh longer by wrapping the stem tops, etc.

I have a PhD in biochemistry. I'm about five years out of the lab (I work at a patent law firm now, so I have a desk job) but I have picked up some hobbies relating to chemicals (e.g., adding patinas to metal, etching copper, etc.). Sometimes I need to do something like saturate the atmosphere of a jar with ammonia vapors, and I might even need to leave it for a few days. Well, I don't want my house smelling like ammonia! I was thinking, well, I would've used Parafilm in the lab to add an extra layer of protection. And then I realized I could probably find Parafilm on Amazon.

If you are not used to this product, it is a stretchy film that does not incorporate an adhesive. It does stick to itself, which is why there's backing paper. It is easy to cut into any width of strip you want (just use a regular pair of scissors, with the Parafilm backing still attached). It is translucent. It will also form to the contours of your container as you stretch it, and once it is applied, it doesn't come loose from glass or metal or plastic or whatever until you want to take it off. (You do have to go all the way around the container so the Parafilm goes back and touches itself. Hope that makes sense. You can wrap around a few times for a better/more secure seal.)

This lasts a long time even if you are not using it; in the past, I had the same roll next to my lab bench for several years without it getting brittle.

It is somewhat heat-resistant. I was doing some experiments where I heated quartz test tubes to something like 260 degrees Celsius in an aluminum block, with the tops of the tubes exposed. I put rubber stoppers in the tubes and wrapped Parafilm around the outside of the stoppers (they were not the right size to bend down over the outside of the tube) to seal in gases from gas-filled balloons I'd put over the tops of the tubes. There was never a smell in the lab, although I was generating all kinds of nasty, nitrogen-containing molecules in my experiments. Anyway, my point is that this product works well even at reasonably high temperatures.

We'd also use this if we were dissolving urea to make polyacrylamide gels. This takes a long time, so we'd mix our reagents in a plastic centrifuge tube, put the cap on, put Parafilm around the cap, and then set it on a rocker to dissolve. No leaks! And of course, there were dozens of other uses in the lab. Now I am using this at home to keep vapors in my mason jars and out of my garage (and/or kitchen, as the case may be).

Anyway, I am always thinking of things I would like to use this on at home and my past experience has taught me that it is a very reliable product. I am happy to be able to get it here (and it is the same quality I have become accustomed to).

Very nice to use

I remember using this stuff in organic and inorganic chemistry labs in the 1970's. Mostly, we sealed test tubes with it. It is impervious to any liquid, stretches membrane thin, and is sticky because of it's waxy nature. Parafilm sticks well to itself, leaves no residue, and in some cases is reusable. Sounds like miracle stuff for masking, right? Well, it is, but I'm still working on that. The potential is astronomic. I have been able to get one nice canopy mask so far, and the camouflage demarkations Parafilm can produce are very thin, unbelievably thin, non-existent, really! Very impressive. But it is not that easy to work with. Stretching it (up to 5x) and then sticking it to the surface is what works best, but stretching it properly is very tricky. The stuff is cheap, thin wax film and doesn't have to be stretched though, I'm just using it as a very versatile masking material.

I use the tape for grafting. Don't waste your time buying the no name knock off stuff from China. That is basically saran wrap. I grafted about 20 avacado scions to my tree and this stuff is invaluable. It's not cheap but it's worth the money and will probably last the rest of my life.