Martin calls this a "Soft Case".  It offers great protection.  The inch-thick rigid foam padding keeps its shape. NOT flimsy!

Exterior is durable dark grey material, inside is light blue velveteen with a padded neck rest.  Stiffer fabric over the peghead protects the padding from tuning posts and strings.

Large exterior accessory pocket, comfortable carry handle, backpack straps, and a grab-loop at the neck edge.  
Extra long to fit the long peghead of a 12-string.