There is a good section on tape thickness in IU's FACET formats document,
linked here, starting on PDF page 9:
1. Tape with a total thickness of approximately 1.77 to 2.13 mils has
a nominal base thickness of 1.5 mils.
2. Total thickness of approximately 1.27 to 1.51 mils has a nominal
1.0 mil base thickness.
3. Total thickness of approximately 0.67 to 1.03 mils has a 0.5 mil
base thickness-- lower numbers (around 0.7 mils) are triple play tapes
while higher numbers (around 1 mil) are double play.
Hope this helps!
Audio Preservation Engineer
Media Digitization and Preservation Initiative
On Fri, Aug 19, 2016 at 12:00 PM, Lou Judson <[log in to unmask]> wrote:
> How do they not match? Too thick or too thin?
> The mil values are for the backing material only, not including the oxide
> or backcoating, as I recall.
> Lou Judson
> Intuitive Audio
> On Aug 19, 2016, at 8:01 AM, Steven Smolian <[log in to unmask]> wrote:
> > What is the best method at reasonable cost of measuring tape thickness
> of a
> > large number of tapes? I'm using a digital micrometer and getting
> > tat don't match the conventional .05, 1.0, 1.5 mil measurements.
> > Am I squeezing the jaws too tightly?
> > Steve Smolian