wood- strong, reusable, recyclable,some issues with overseas usage "insects transportation" (I think), potential cross contamination from pallet to some products.
plastic- strong, reusable, recyclable, inert, may last a little longer than wood, little higher cost than wood.
metal- strong, reusable, recyclable, inert, may rust, damage by bending/warping, should last longer than plastic or wood, cost more.
I'm sure there may be things I missed about the three different types of pallets.
These points i listed were somethings off the top of my head.
Maybe some others will add to my points. Hope this helps.
Charles
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Metal is the material, The forge is life, The anvil and hammer bring character and soul.