Abstract: A base for a sealed package used to ship or store a large and valuable asset is formed by drilling the base to receive a bolt array, placing the bolts in the drilled bolt holes, punching holes in a sealing layer to fit over the bolts and rest on the base; applying sealant material around each bolt below and above the sealing layer to seal the junctures between the bolts and the sealing layer; and preferably arranging a protective layer over the sealing layer to leave an exposed perimetal region of the sealant layer extending continuously around a protective layer. The bolts are used to fasten the asset or a carriage for the asset to the base, and a flexible top cover with a bottom region engaging the peripheral region of the sealing layer is then bonded to the sealing layer to seal the asset within the package.