The right way to use spacer in bed to raise camper?

[FireGuard]

I just got the tiedowns installed and ready to mount my Lance 815.
I need to raise the camper about an inch to keep it from riding on the bed rails.
I have Linex and a rubber mat and will probably use a sheet of plywood.
Should I put the plywood on top of the mat and let the camper rest on the plywood, or sandwich the plywood between the Linex and rubber mat.
What will give the best "traction"

[FireGuard]

All great info, thanks.

[69_Avion]

I had two layers of 3/4" OSB which weigh about 150#. I took them out and put a couple of layers of the pink styrofoam insulation which weigh about 10-15#. The camper hasn't sunk down yet and it doesn't slide around since I have guides in the bed anyway. It's nice to save the weight.

[WNYBob]

I added a 2x2 frame on the bottom of my 2004 TC to get off the rails. No worries about adding things needed to load the TC!

[kohldad]

I had the same issue with my Lance 815 when I upgraded from a 2004 to 2015 Ram. I built an interlocking frame of 1x6 and filled the void with 3/4" foam. Plenty of clearance and a much warmer floor. To keep it from sliding around on the wood, I lined the 1x6 with a strip of anti-slip shelf liner. Haven't moved yet.

I like the full support the horse mat stall but didn't want the weight.

[Buzzcut1]

[FireGuard]

Thanks Buzzcut
I didn't know they were that thick.
Reason to visit Tractor Supply.

[Buzzcut1]

I found that my lance slid round on plywood do matter how I tighted my tiedowns. Now I just use a 3/4" thick horse stall mat in the bed. nothing moves.