I get those big yellow envelopes with bubble wrap 
inside them I believe-get a dozen for like 12 
bucks at Staples. I have lately been putting the 
cel into the yellow envelope, with like putting 
cardboard around the cel. Then seal that up, 
secure it and then throw it into the box. Only a 
buck each and well...it's safe. Sometimes just 
send the cel in the fat protective pckage if the 
cardboard is like steel and sturdy then protect 
that too.