How does nitrocellulose produce less smoke than black powder?

Nitrocellulose produces significantly less smoke than black powder because of the fundamental difference in how they combust.

Black powder is a mixture of saltpetre, sulfur, and charcoal. When it burns, it produces approximately 60 percent solid products, which appear as a thick, whitish smoke.1

In contrast, nitrocellulose is an inherently unstable compound that decomposes rapidly upon ignition. Unlike the chemical reaction of mixed ingredients in black powder, nitrocellulose combustion converts almost entirely into hot gases. Because it leaves behind virtually no solid residue, it is commonly referred to as smokeless powder. This transition to a gaseous state not only reduces smoke and flash but also allows for more efficient mechanical work per unit of weight compared to traditional black powder.1