Glass shells made from the pyrolysis of silicon-doped glow discharge polymers (Si-GDP) are particularly interesting for many noncryogenic target applications. We investigated the possibility of developing millimeter glass shells with >10-m-thick walls to achieve a half-life of several months. Although previous studies have already demonstrated their feasibility, important developments are still needed to finely understand the role each step plays on the final glass shell's properties. The adjustment of plasma deposition parameters and pyrolysis conditions allowed us to control shell shrinkage and defect formation. In the case of 7.4 at. % Si-GDP slowly pyrolyzed, we obtained spherical and smooth glass shells with near 100% yield. We also demonstrated that adjusting sintering temperature can produce fully dense glass shells from 2.2 to 2.4 g/cm3 . Finally, deuterium pressurized capsules >3 MPa with a half-life of 8 months are obtained.