Gusset boards of a blown film extrusion apparatus have nose portions that can be positioned in the path of a tube of blown film traveling between the nose portions where the nose portions engage with opposite sides of the tube of blown film and form gussets in the tube of blown film. The nose portions of the gusset boards can also reduce their width dimensions which enables the nose portions to be moved away from the path of blown film traveling between the gusset boards when gussets formed in the opposite sides of the tube of blown film are not needed.