Underneath mattress protection from plywood platform?

Have a king size Shovlin pillowtop coil mattress coming, dual sided flippable. I am putting the mattress alone (no boxspring) ontop of a plywood surface. My base is an Ikea platform with slats, I then put 3/4inch plywood over the slats to provide a very solid non sagging base. The mattress will sit down into the base between the wooden side rails about 3 inches.
Im looking for a material I can lay ontop of the plywood to protect the mattress from wood splinters, discoloration, etc. Basically I dont want to lay the new mattress on bare plywood. Anybody have any ideas?

Hi needanemattress,

You can see my thoughts about a solid surface support system in post #10 here and I think that the bedrug here or the slat conversion kit here (you can see the prices here) would both make good choices to provide additional ventilation under your mattress and protect your mattress from the plywood as well.

Phoenix