1. A carrier and article system for transporting a plurality of articles on a convey line of a microwave heating system, said carrier and article system comprising:a frame configured to engage said convey line;
an upper support structure and a lower support structure coupled to said frame and defining a cargo volume therebetween; and
a plurality of articles received in said cargo volume, wherein each of said plurality of articles includes a top and a bottom, with a length of the top of each article in a first direction being greater than a length of the bottom in the first direction,
wherein said plurality of articles includes a first article and a second article arranged in said cargo volume such that the first article is oriented top up with the bottom of the first article contacting the lower support structure, the second article is oriented top down with the top of the second article contacting the lower support structure, and the first article overlaps horizontally with the second article.