Hi, Nigel,

Thank you for this very useful insight! This has been part of the mantra 
for a long time, but it is wonderful to receive further confirmation.

We cannot forget the "running changes" that Benoit Thiebaut discovered 
specifically in U-Matic tapes, but I suspect that process "improvements" 
were common as tapes were running and if this 60-70 % factor is involved 
it doesn't even have to be a process improvement.



On 2013-04-05 4:53 PM, Nigel Champion wrote:
> At last year's IASA conference in New Delhi, Dietrich Schueller presented information gleaned from discussions with retired employees of the major German tape manufacturers, BASF & AGFA.  Some expressed the opinion that subtleties in the manufacturing procedures had more influence on the finished quality of magnetic tape than the actual chemical mix by a factor of 60% or 70%.
> I infer from this that, even if one tape has exactly the same chemical constituents as another, a small variation in one step of the manufacturing processes can result in pronounced differences in measures of quality such as performance, stability and/or longevity.  Such a situation makes comparisons very difficult at this late stage for those considering chemical analysis of constituents or assessing differing degradation under controlled climatic conditions as suggested recently on this list for sticky-shed.  It would also explain the differing experiences of many on this list with the "same" tape.
> Nigel
> ________________________________________
> From: Association for Recorded Sound Discussion List [[log in to unmask]] on behalf of Tom Fine [[log in to unmask]]
> Sent: 06 April 2013 07:23
> To: [log in to unmask]
> Subject: Re: [ARSCLIST] Sticky SHRED
> I think Dennis is bringing up a really important point. Sarah and Richard, do you have any contacts
> with original tape manufacturer chemists, people who were familiar with the "brew" of the tapes?
> Before these people die, it's important to get information from them about what chemicals were used
> in the binders. There's no "state secret" anymore -- all of those tape manufacturers are out of
> business now (and I'm afraid, given how things work, that corporate records detailing the "brew" are
> probably lost to time).
> <SNIP>
> -- Tom Fine

Richard L. Hess                   email: [log in to unmask]
Aurora, Ontario, Canada                             647 479 2800
Quality tape transfers -- even from hard-to-play tapes.