The interior air and vapor control layer went up super quick and easy. The paper is manufactured with a waxy feel - and pleasant fragrance.
This layer is designed to prevent moisture (vapor) from the getting into walls; conversely it permits walls to dry to the interior if moisture does somehow get into a wall cavity. It’s also an air-barrier that will help keep outside air from entering the building envelope.
The Siga Majrex sheets were easy to cut and went up so smoothly. The waxy coat made corners easy to get into and hold while adding staples. For those interested the paper and tape system is also non-toxic.