Clear Vinyl will shrink about 1-3%. Overtime the plasticizers inside the vinyl dry out. As that happens it causes the vinyl to slightly shrink and tighten up. High heat environments will usually cause it to dry out a little faster (Example: storing it in a hot attic). The clear vinyl will also shrink a little after it is unrolled for the first time. The manufacturing machines wind the rolls so tightly they need about 24 hours to relax to remove the stress built up in the roll.