My tarp-tent is now also complete, I made this from Tyvek hardstructure using double-sided bonding tape bought from Tread-Lite gear. This stuff is truly brilliant and works really well with Tyvek.
The sides of the bathtub as 5″ deep, with adjustable shock-cord loops at each corner and halfway along the long sides of the groundsheet.
I’ve also added open topped pockets to keep things like my watch and headtorch handy, these pockets being ideally sized (and accident) to allow the tarp to fold into when packing.
It’s light, it fits the tarp well and I’ve very happy with it.
My next jobs: stuff sacks for pegs and the tarp, then a set of waterproof mitts and I’ll be set to go.