How to distingusih acetate vs poly base without tearing it?

[Winbert Hutahaean]

I am now in the middle of separating films printed on acetate film base which will eventually get VS in my humid and hot country. I have often read that those films printed on poly (mylar) will not be affected by VS, right?

So how can I distinguish it without tearing them. I knew by tearing the acetate will just easily break but poly will not that easy. But it is so painfull to tear the leaders for this purpose just in case there is a simple way.

Anyone?

[Phil Murat]

Hi,

In this picture , "Inner Disk" is Polyester, much more translucid :





In an other way, "Triacetate" is a bit thicker than "polyester", you need a caliper in that case.

[Graham Sinden]

Winbert,

hold a piece up in the air and let it hang down. Acetate will have a 'curl' to it whereas Polyester will hang strait down.

[Nantawat Kittiwarakul]

- Poly's base side is usually a bit more "reflective". Acetate would seems dull compared to poly.
- Poly would be usually a bit noisier when projecting compared to acetate (possibly due to its "rigidness"). The larger film gauge the more pronounced the difference.
- Poly's physical dimension will stay virtually unchanged, while acetate will eventually shrink down somewhat. Place them side by side and you'll see the difference. You don't need that much length - 1 1/2 feet will do.

[Winbert Hutahaean]

Hi,

In this picture , "Inner Disk" is Polyester, much more translucid :

In an other way, "Triacetate" is a bit thicker than "polyester", you need a caliper in that case.

Thanks Phil...I guess now I know which one is poly film base from my photo above.

But with Graham's additional input, I think this is much simpler. Will that method apply to both color and B/W films?