#DIY #MYOG Weight: 2.2 oz Bathtub Wall Height: ~6 inches Material: Polycryo Window Insulation (Shrink wrap) Time Required: 15 min Materials Needed 1. Dollarama 40" x 64" Window Insulation Kit - $1.25 each (x2) -Using window insulation material for a cheap and light backpacking groundsheet is nothing new, but usually the kits still cost at least $10 - this Dollarama kit is a steal. The only problem is that the dimensions will be too small for most people to use just one sheet,