Rack Material Plywood/Melamine

I'm going to be building a rack system soon similar to the sticky setups on this forum. Most people seem to use melamine. I would prefer to use spruce plywood if possible, I would be using Varathane on the plywood surface to protect from moisture. Has anyone else used plywood instead of melamine? Will the plywood hold up to the moisture? Will it start to sag after so long? I guess what I'm asking for is the pros and cons of melamine and plywood, I would just prefer plywood for looks.

Thanks

You know you can get melamine with a faux stained maple look to it

All I use is birch when i build my racks. Plywood is so much lighter than melamine. Mine comes prefinished with a 2 part epoxy finish that is baked on. Much more durable than anything you can apply yourself. Check with a local cabinet shop about selling you some

Heres a shot of the inside of one of the cages i built with it.

http://i1201.photobucket.com/albums/...s/DSC06048.jpg