Parafilm | What is this thing?!

What is this thing?

This is Parafilm.

Parafilm is the lab version of plastic wrap except way better.

Parafilm is made from paraffin, a waxy substance

derived from petroleum that we normally

think of in stuff like candles and wood polish.

Parafilm is great because it's stretchy,

and it sticks to itself, and it's waterproof,

so it makes it great for sealing things.

It's most often used in the biology lab

to steal plates and bottles, and it's also a great palette

when mixing small quantities of liquids.

Parafilm is ubiquitous in labs.

It's useful.

It's kind of fun, and it's really just everywhere.

It's the only thing like it in the lab,

and its packaging seems to have remained unchanged

for many years.

So when my lab's summer students suggested

that I do a "what is this thing?" on Parafilm,

I decided to do some digging into this stretchy lab staple.

Now, I couldn't find a lot about the invention of Parafilm

online other than the fact that the trademark

was filed in 1934 by the Marathon Paper Mills Company.

It was classified as a moisture-proof, self-sealing

flat wrapper, and the trademark was later

acquired by Bemis, the current manufacturer of Parafilm.

I couldn't find much more information about its invention

online, so I reached out to Bemis

to see if they had anything that they could share with me.

They did send along a little bit of information,

but first they actually sent me a big box of Parafilm,

so I let the summer students who inspired this video open it.




Oh, my god.

Oh, my god.

That's really big.

We can wrap Anna in this.



All for free.

Oh, my god.

All right, well, we're going to have Parafilm for a while.

Parafilm party.

Bemis did also send along a little bit more information.

From their email, they said, since the commercialization

of the product in the 1930s, the formulation has

remained virtually unchanged.

The original end use was listed as map

mounting although no one knows exactly what that entailed.

So clearly, my first task was to figure out

what map mounting is.

It took a little bit of searching,

but I found a book called The Fundamentals of Cartography

that suggests that paper maps that

are going to be handled a lot, like in a library,

should be mounted on a sheet of cloth.

One of the ways that they recommend

doing this is called dry map mounting, which takes a paper

map and sticks it onto a piece of fabric

imbued with paraffin wax, using a hot iron.

So perhaps-- and this is just my hypothesis here--

Parafilm was first invented to be this paraffin film that you

could put between a paper map and a piece of fabric

to stick them together.

Now, this hypothesis is supported

by a 1952 popular science advertisement

for Parafilm, which suggests that you can stick photographs

printed on thin paper onto a sweater or jacket by putting

a thin piece of Parafilm in between and then ironing it on.

It's not perfect, but I can definitely

see how this would make a map a lot more durable.

Bemis also sent me a list of uses of Parafilm

that they had aggregated from their customers

during interviews, and they wanted

to point out that they do not necessarily

endorse all the uses in this list,

and I also would like to point out

that I do not necessarily endorse

all the uses in this list.

Here are a couple of my favorites.

Preserving open wine as a cork replacement,

replaces missing earring backings, sealing containers

prior to flying, put on the end of screwdrivers

to hold screw in place, earplugs--

this is not comfortable.

I also asked on Twitter for your favorite uses of Parafilm,

and I got responses ranging from stealing whiskey bottles

to using a long piece of Parafilm

and a string as a cat toy, and I love the diversity of uses


I also found entire Reddit threads

of people proclaiming their love and their many different uses

of Parafilm, and I'm going to link those in the description

box below.

So what is this thing?

A much beloved lab staple.

I want to note here that this video was not

sponsored by Bemis, the makers of Parafilm.

In fact, I reached out to them, saying

that I was making this video.

But they did kindly send me some Parafilm, which I appreciate.

So thank you to Bemis.

But this video was supported by my wonderful, fantastic

Patreon patrons, who make it possible

for me to do crazy stuff like this

and to spend a lot of time babbling about a lab supply

that I and many other scientists love

and make this sort of unusual "what is this thing?" video.

In fact, I have also filmed and recorded

this video entirely on equipment that Patreon allowed me to buy.

So thank you so much my Patreon patrons, and also a shoutout

to our lab's summer students, who inspired this video.

Go forth, and do well-sealed science.