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I have a material that came from a coffee bag and I want to know what it is? Answered

All I know I have this coffee bag and I can see threw one side of it and not threw the other. I want to use it for an instructable but I need to know what it is so other people can make my project. Thanks for the help.


It is some kind of metalized plastic film,


and it is also likely a laminate. That is to say it is likely a sheet made of more than one layer, and the layers can be made of different kinds of plastic.


One of the oldest metalized films is metalized BoPET, and sometimes people call that stuff Mylar(r), since that was the trade name given to it by Dupont, the company that originally made it.


Sometimes you can find metalized BoPET in the sporting goods aisle, sold as a thing called a "emergency blanket", and this thing is a rectangular sheet of mylar about the same area as a blanket. I've got one in my desk drawer, still in its original packaging, and the package says it's 1.3 m by 2.1 m. As it is now, in its folded up state, it has about the same volume as a deck of playing cards.

I have no idea if this contrivance could actually keep a person warm, like if he or she was like stranded in the wilderness somewhere. But, you know, the marketing is solid. They sell 'em in the sporty goods aisle, and in stores that sell camping and outdoorsy stuff.

Also one way to tell if you've got a piece of metalized film, with just one layer, not a laminate, is the metal layer has measurable electrical resistance. Just put the probes of your ohmmeter, or multimeter in resistance measuring mode, on it, and you'll get a reading.

In contrast, the plastic side, of the same "emergency blanket", has resistance too large to measure (>2.0e6 ohms, since with my multimeter, top scale is 2.0 mega ohm) with the probe tips about 1 mm apart.

Space blankets are very effective at keeping body heat in and wind out.

I will take your word for this.

Although I suppose I could try it myself. It has been kind of cold here lately, what with it being wintertime and all that.

I'm thinking I'd get the maximum effect by wearing it covering the top of my head, kind of like a hoodie, in contrast to the picture of the male model on the box.

(See the attached picture.)

I'm not quite sure about the expression on the face of their poster boy. Maybe they told him to look serious, because it's an emergency blanket.

Or maybe he's wishing that he were modeling some more fashionable clothing. Ha!

I dunno. Perhaps the reason his head is uncovered might be because the advertising peeps thought the picture looked better that way, which is maybe like a still photography example of one or both of the movie tropes linked below:

Helmets are Hardly Heroic



In Space Everyone Can See Your Face



I was (guess still am) a certified outward bound instructor. We had to carry a couple of space blankets in case of emergency. We also carried survival bags & sleeping bags.

Although to keep a person warm it was recommended to cover the head as well apparently you don't lose any more heat from your head than anywhere else. So keeping the body warm is the essential part. I always though the blanket were made for midgets and didn't cover much below the waist.

Like the two links :-)


Polarized laminated film and packaging, one way to be sure, hold two sheets next to each other, turn one 90 degrees it will ether go from transparent to dark where you cannot see through it or it will go from dark to transparent where you can see through it.

They are kind of like the mirror sun glasses cops like to ware.


1 year ago

Something has damaged the mylar. Most coffee bags are roasted beans in a light proof sealed two,sided mylar bag that can be resealed many times and is heat sealed above where someone cut off the heat seal... A coffee roasting plant may give you a 1LB or a 5LB empty bag if you ask nicely.

Why the dog picture ?

sorry thats just my porch from the inside of the bag. I guess the dog just wanted to be on instrucables : ). So could i use this for an ible cuz people can replicate it?

Sure there are thousands of coffee shops that throw those bags away.

I don't know who makes a clear sided bag.. Probably for food stores to let people see the inside contents... If coffee is what is inside, I would think it is a low grade product...

So it's a porch with a pooch.
Which reminds me of something: the words "through" and "threw", are not the same word. I know that maybe sounds crazy, but it's true. You can look it up.

Actually looking it up is left as exercise for the interested reader.