I'm home again and was finally able to check my old literature.
#140 was 1 1/2 mil acetate and 141 was 1 1/2 mil polyester base. This is what I wrote up on the chart back when it was put together in 1995 or so. I can't explain the box Mr. Bal has unless it was an early product we made at one of our European plants. Is there a manufacturing site or country on the box? It could have been made in Italy or Wales.
To make matters more difficult, we never published tech data sheets on the 140 series as it was sold into non-professional markets and didn't require data sheets. Thus I have to trust my memory when I put the chart together in the mid 90's.
I notice that in Delos Eiler's list on the AES web site, Scotch 141 is listed as "polyester", but the 141 box I have right in front of me says acetate. Is this a typo? The tape inside the box sure looks like acetate.
Thanks
Marcos Sueiro Bal