I have shipped many, many models built and unbuilt through sales on ebay and this is what I do for an unbuilt kit. I wrap it with bubble wrap and tape it. I then use a priorty box from the PO that they call the shoebox box. It is perfect for normal size model boxes. I then stuff bubble wrap in the bottom of the box, slid the kit in and add bubble wrap to the end as needed. I have never recieved a complaint and all my items arrived in good condition.