To quote my insulator mentor; Mike Bliss on packing insulators for shipment "Movement is the enemy". So with that in mind I try to not to leave any voids in a box. Sometimes I will make a cardboard cylinder or pack a small box full of packing within a box just to fill in the voids. I have even sent an extra common insulator as "packing material". I usually label it as bonus or free, so as not to confuse the buyer about an insulator that was not paid for. If I have packing peanuts, I use them in the smaller voids.

When I pack tapered insulators like beehives, I turn them base up and then base down this allows more packing material to fit between them. The "stagger" also prevents "impact points" at the bases if they were all in the same direction. An impact to the box will slide all the contents toward the impact point and one insulator could break an adjacent one right through the padding between them. In this medium rate box I have dividers between pairs of insulators.