I can not remember which thread I posted my full explanation in about shipping long boxes, but it was already mentioned that use two lids. One for top and bottom. The sides I add a layer of foam board( what I usually use for all of my shipping. ) I prefer to use foam board as it is stronger and sheets can be bought from dollar general usually for $1. I also use bubble wrap and water activated security paper tape. (Makes it stronger and I already have it due to Registered expensive packages and I