COMFORTABLE. Starlight Support™ mattresses are available with high-density foam or innerspring support in standard or custom sizes. Either option offers two levels of comfort. One side offers a firmer surface for newborns, while the other is slightly softer to help older babies sleep more comfortably—more peacefully—through the night. Both are engineered within SIDS reduction guidelines, designed with pressure-reduction techniques that come from years of experience in hospitals and health-care facilities.  I wish I had known about these mattresses before I had my twins.  I never realized there were mattresses with different levels of softness.  By 12 months old, we could tell that one of our twins was very uncomfortable in her bed.  She would toss and turn all night.  On any other mattress in the house she was fine.  By 19 months she refused to sleep in her crib and slept through the night from day one on a regular twin mattress.  The Starlight Support Mattress is definitely a necessity for any crib. 

Moonlight Slumber Starlight Support Crib Mattress