Bed Mat - To make the bed flat

I use cardboard or plywood!

If you are going to make your own, maybe you could use this... https://www.tractorsupply.com/tsc/product/4-ft-x-6-ft-x-3-4-in-thick-rubber-stall-mat?cm_vc=-10005 These are 4x6'x3/4" and weigh 100lbs. Post pictures of your install when your done!

Thanks guys for all the info. After looking at everything I think Im going to make my own of HPDE plastic (same plastic Decked uses) I can get two 48x96" sheets for about $90 each plus shipping and then buy a cheap rubber bed mat ($90) for a template. I'll come back to this post once everything is done.