Name that plastic!

What kind of plastic is used for stencils like this:

The only details I ever see are “green, translucent, flexible plastic.” But what kind of plastic is it?

I would say polypropylene

do a burn test on a corner…

or google :wink:

polypropylene stencils

What do you mean by a burn test? Should polypropylene do something unique when it’s burnt?

Plastics all have different burn characteristics, some smoke, melt, hold a flame, smell a certain way. You can find the information online. Many designers have a cigarette lighter in the drawer to burn the corner of a piece of plastic to determine what a part might be.

The best is if you have spent time in a plastic molding facility, you can recognize the smell of the lit sample from the smell near a given injection machine when a part is being injected.

+2 for old school baby.

just don’t inhale! I try to identify it from sight first… smell is last.

Awww man this is a good score.

this is all you need for the burn test!


Polypropylenes - Acrida Yellowa Yellowa Sweet Blue,
yellow tip Yes Slow

Floats in water;
more difficult to scratch
than polyethylene


Thanks for all the help. After the explanation of the burn test, I searched the web and found that same website mentioned above plus a few others. I’ll keep those handy for future reference.

Did you get any results? I remember back in school, a few classmates of mine were experimenting with materials to create their own custom stencils, and were having a hard time identifying the right material.

Back in the day, and I do mean back, drafting templates were made of acetate, it had a particularly acidic smell, as I recall.
Acetate sheet is available from a lot of art supply dealers’ .005-.125" thick and it’s relatively easy to cut and score.

Sheet styrene is another good choice for handmade templates. Really easy to cut and shape, although it’s notch sensitive so you have to be care with it.

I have a set of 1/8" thick Copenhagen Ships Curves that are plexiglass (acrylic).

WHen I was in HS, I thought that there was still a chance that when I graduated Uni I could have a few hundred stencils and do manual drafting. Sadly, computing overtook my ambitions :~(

Impact modified acrylic (green) per