There are many different parts to a cigar, but none so as important as the filler used in its construction and the effects of aging in a humidor on that filler. The filler is responsible for about half of a cigar’s taste, and, as you might imagine, is one of the most important parts of a good smoke. So, what is cigar filler? In essence, filler is nothing more than the tobacco used in the interior of the cigar – it’s what the wrapper holds together. Depending on the area where the filler originated, you will find different tastes and aromas.