Each section of a blend must always contain the same number of entities, with the exception of capping a blend. For sections that do not have enough geometric entities, you can add blend vertices. Each blend vertex adds one entity to the section. A blend vertex acts as a terminator for the corresponding surface of the blend, but it is counted in the total number of entities for a section.

You can use a blend vertex in either a straight or smooth blend. In smooth blends, only the first and last sections, in geometric sequence, can contain blend vertices.