Jim Walsh of Ampex recommended using Pellon fabric (available in 
sheets of various weights at fabric shops, but also seen some time 
ago as ribbons of various widths on spools for tape cleaning). Pellon 
is a non-woven synthetic fabric (i.e., one that does not shed). It's 
been useful here for mild deposits from "sticky-shed" syndrome (which 
I seem to have had the dubious honor of "discovering" -- never wish 
for "fame" -- your wish might be granted) and for cleaning dust and 
dirt. The main caution is to set up your cleaning so that the debris 
captured does not fall into the works of your machine and cause 
problems that you didn't have before.

I'd recommend avoiding use of most foreign substances (others may 
know of beneficial ones) and of paper towels, cloths of normal 
fabrics such as cotton, or anything else that would shed and thus 
create dust or debris and making sure to do the least possible to 
achieve one's purpose (one can always repeat a cleaning run, but it's 
a bit difficult, if not impossible, to put back anything that's 
rubbed off that shouldn't be, such as the oxide that contains the 
recorded signal).

Cleaning cassettes is a task that gives me the horrors; I'd recommend 
seeking an expert for such work if one has more than half a dozen. 
It's gaining safe access to the tape itself that's the issue in this 
sort of task. I believe it may be your teacher who was the expert 
recommended to me by several colleagues for cleaning and rehousing 

I hope you'll hear from some of those on the list who have developed 
machines and special techniques for tape cleaning, as I've learned a 
good deal from them via this list.

Sincerely, Richard

  At 12:20 AM 4/4/2007, you wrote:
>Hello all,
>I am joining several of my classmates in seeking the wisdom of folks
>on this list...  I am researching cleaning procedures for analog tape
>and cassettes. What types of issues are involved here?  How do you go
>about the process of cleaning tape, if you do?  If not, why?  Are
>there products or procedures you would recommend or, conversely, avoid?
>We are assembling a guide as part of a class assignment (due April
>17).  Any information or resources you could point out would be
>greatly appreciated. Please feel free to email me off list -
>[log in to unmask]
>Thank you very much,
>Laura Mundee
>MSIS Candidate
>School of Information, University of Texas at Austin