Shipping Bare Root Trees

Hey! This year I grew a few hundred trees from seed, most of them are tiny around 10 inches, does anyone have experience shipping these type of trees? How would you package them?

Select a long thin box where the seedling can be placed completely straight.  The trees I've myself received through the mail were wrapped in wet burlap.  Overnight shipping is mandatory.  Include instructions to soak the roots in a bucket of water for a couple of hours before planting.