I use non-adhesive "sill sealer" stiff poly foam gasket from a roll to protect my hones for travel. About 5 bucks for enough to separate all your hones and with yards left over. The 5½" inch seem to be best but a couple three inch widths would work also. Available at any lumber yard or building store. Good for protecting anything I ship. Won't pop and lose its protection like bubble warp. You can make bags of it of you want by using packaging tape.
~Richard