Here are two additional methods to determine if the audio tape is acetate or polyester:
1. Polarization Test: Place the tape between two sheets of polarizing filter. Polyester tape will show color fringes (similar to oil on water) when viewed through the filters, acetate tape will not form these color bands.
2. Utilize Acid-Detection (A-D) Test Strips: The strips change color to indicate the amount of acetic acid present. Polyester tape will not make the strips change color. These strips are usually utilized with motion picture film, but can work with audio tape. They are also a better way then smell to determine the level of Vinegar Syndrome.
Preservation & Media Specialist
The Georgia Archives
5800 Jonesboro Road
Morrow, GA 30260
[log in to unmask]
From: Association for Recorded Sound Discussion List
[mailto:[log in to unmask]]On Behalf Of Richard L. Hess
Sent: Monday, May 03, 2004 3:41 PM
To: [log in to unmask]
Subject: Re: [ARSCLIST] acetate tape
You could pull at the last 1" of the tape and see if it stretches or
breaks. If it stretches, it's probably not acetate.
3M 201 was a late acetate tape that might be darker. I don't know about the