Mylar bags (sealing only) – Wait 60 seconds between each seal. This is to ensure the temperature bar doesn’t’ get too hot and cause damage to the unit. Start with a lower temp option to find the best seal.Mylar bags (vacuum sealing) – The bag needs to have at least one side textured. If both sides are flat the bag can only be sealed, not vacuum sealed. The bag thickness can range from 50-250 micron (125 max single side thickness).