Fleece and plastic film are both good for protection against the cold. If you are using film, you must ensure that the film has holes or slits in it, otherwise large amounts of moisture will collect under it. Fleece has the advantage of letting more air in to the plants underneath. For this reason fleece is preferred, especially for later plantings.
Have fun working in your garden!
Best wishes from Waibstadt
The T.I.P. Team