10 12"x12"x8" boxes from the USPS for sending hatching eggs in. Are these measurements efficient for this job? I just didn't want a box too small so where I couldn't put enough bubble wrap, shedded papper and all that packaging material. And I didn't want a box too big because I don't want to be charged for unwanted wait. So tell me, is this a good sized box to ship say, a dozen? Thank, Grant.