|
|
Home Page | Message Boards | News | Archive | Ask Cecil | Books | Buy Stuff | Cecil Who? ]
Dear Cecil:
The other night I went to see John Waters's movie
Polyester, filmed in Odorama, which enables you to smell
certain, ah, unique fragrances periodically via a
"scratch-n-sniff" card. I was hoping you might be able to explain
to me the principles of "scratch-n-sniff." How does it work and
how can I make my own? I have some interesting Christmas card
ideas. --Patrick W., Milwaukee
Dear Patrick:
I'll bet you do, you
deve. The basic S&S process, called Micro-Fragrance Coatings, was
invented years ago by the 3M Company, and is intended for
the transmission of happy fragrances such as daffodils and
buttercups, and not some evil reek such as you and your
weirdo friends are likely to come up with. Which is not to say
that, in my younger days, the same idea wouldn't have occurred to
me.
Smell, to begin with the
basics, is a matter of molecules dislodging themselves from a
substance's surface and finding their way into your nose. To get
something's smell on paper, its molecules, or a lab-bred facsimile
of same, must be distilled into a sort of perfume (i.e., a highly
volatile liquid) that is insoluble in water. Then 3M emulsifies the
liquid, which essentially means they dump it into a giant Waring
blender and whomp the bejeebers out of it. Since oil and water
don't mix, we end up with millions of tiny bubbles of essence
suspended in liquid. By means of a magical proprietary process that
3M has sworn me never to reveal, the bubbles are then conveyed into
a plastic goo, which can then be used like ink and printed onto
(preferably) some sort of stiff card stock with a modified printing
press. When the plastic carrier dries, the bubbles of liquid are
trapped inside until you scratch (the card, I mean), whereupon they
break open and become smellable.
A similar process is used to make
carbonless copy paper, only the bubbles are filled with a special
chemical instead of a fragrance. When you press down with your pen,
the chemical is released from the back of the top copy and reacts
with another chemical coated on the front of the second copy (got
that?), producing the inky stuff that makes the copy.
The bubbles,
you may be interested to know, are something like half a thousandth
of
an inch in diameter and there are roughly 50 million to the square
inch, so this is not something you can whip up in the kitchen. 3M
will be pleased to knock some out for you, though. All you have to
do is buy enough for about 50,000 copies.
--CECIL ADAMS
The Straight Dope / Questions or
comments for Cecil Adams to: cecil@chicagoreader.com
Comments regarding this website to: webmaster@straightdope.com
Copyright © 1996, 1997, 1998, 1999 Chicago Reader, Inc. All rights reserved.
No material contained in this site may be republished or reposted without express written
permission.
The Straight Dope is a registered trademark of Chicago
Reader, Inc.