Usually, the factory produced most emulsion in format W/o. Because if I o/w will cause some oil to the outside edge and bottom of the container. Cause an aberration and not the texture I want.
Typically, the majority of manufacturers are making emulsion to form a W / o. If you do, o / w oil to make some stuck on the edges and bottom of the container. Cause errors and is not in desired texture.
Usually, most factory will do emulsion in the form W / O. Because if you do o / w will make oil, some trapped at the edge and the bottom of the container. Cause error and not texture in need.