New Laminate Storage

I am doing new kitchen countertops using Wilsonart HD laminate. I have the laminate on order and it should be here a few days. When I pick it up I am expecting it to be rolled up. Between fabricating the new countertop underlayment (particleboard) and other commitments it will be a few weeks before I will be installing the laminate. How should I store the new laminate? Leave it rolled up or lay it flat.



Thanks