Glassco manufactures glass containersbottles and jarsfor the food processing industry. Most of the employees work on production lines tending molding machines that extrude the containers. Glassco also employs some skilled glassblowers, who create crystal decanters. The glassblowers are skilled artisans who work in a separate area of the plant and fashion the decanters using molten glass and rudimentary hand tools. Because of their specialized skills, the pay scales for the glassblowers are higher than for the production workers. All the Glassco employees are represented by the International Molders Union, and are grouped together in one bargaining unit. The glassblowers feel that their interests are not being adequately represented by the union because there are only a few glassblowers, compared to the hundred or so production workers. The glassblowers file a petition with the NLRB to form their own union, the Glass Artisans Guild. Should the NLRB sever the glass- blowers from the production bargaining unit? What factors will the NLRB consider in making its decision