In MMD 140130 Nicholas Simons indicates to buy the CML or CTL if your
rebuild requires a completely sealed leather.  I must chime in here
because if you test this leather, you will find that its sealing
property is better than the original CPL leather but it is far from
being a completely sealed variety.  And you will be surprised at how
much it leaks if you buy the extra-thin variety.  The "Thin" is better
but is far from being 100% air tight.  It will still require sealing.

I built a tester about 14 years ago made from Plexiglas as seen in the
links below.  You place the leather between the tester and another flat
piece of Plexiglas and apply suction to a hose that pulls air through
the leather.  You can then compare different leather types and sealer
techniques to see what works best.  In the tester it shows CTL X-heavy,
which is far too thick for pouches but has good sealing properties, but
not 100%.

Pete Knobloch
Tempe, Arizona

 [ http://www.mmdigest.com/Attachments/14/01/31/140131_150809_DSCN4955_949.JPG 
 [ http://www.mmdigest.com/Attachments/14/01/31/140131_150809_DSCN4956_950.JPG