“Travel stain” is a phrase often heard in conjunction with comb honey. Travel stain is the discoloration of wax cappings covering the honey due to the “dirty feet” of honey bee workers.
In the normal course of walking from place to place in the hive, the worker bees track pollen, propolis, and other debris across the surface of the comb. The cappings take on an unpleasant yellow or brownish cast that is darkest in the main pathways and lighter toward the edges of the frames or section boxes—much like a carpet in a busy room.
In order to reduce travel stain some beekeepers eliminate the upper entrance. Forcing the workers to use the main entrance means they must walk further to get to the comb honey supers. During all this walking, a large part of the debris is left in the brood boxes and never makes it into the honey supers. Other beekeepers try to remove the comb honey sections as soon as they are are capped, or at least move them to the outside rows of the super where they will receive less traffic.
Travel stain is one of many problems that makes the production of comb honey more labor intensive than the production of extracted honey.