Flexible PVC used as skin for Ziptrak blinds becomes stiff in cold weather, this stiffness will prevent the skin to slide down the Ziptrak tracks as it is maintaining its shape when it was on the top keyway tube. The PVC stiffness is not a problem with a manually operated Ziptrak blinds, but in a motorised Ziptrak blind, the weighted bottom rail cannot always overcome the PVC’s stiffness.