Stephen, The reason I asked about packing is because I recently used vinyl shade slats with my 8/4 cotton warp on a small table loom. I was accidentally deforming the slat ends as I was winding on, and winding a smaller circumference at each end of the beam, where the slats were squeezed together by my hands as I was winding on. This created a wonky warp. I ended up having my husband help me unwind and rewind with attention to the slats and the stacking of the warp as it made its way onto the beam.
I was also wondering if the corrugated type packing could cause some distortion of the warp, as it was being tightened and crushing the paper structure.