1.0 Renders completely opaque objects while 0.0 will be transparent. Objects written after this will have a combined transparency value with the group transparency if it is set (e.g. 0.5 for group and 0.8 stream will result in 0.4).

public void Transparency(
	double d1
)

Public Sub Transparency ( 
	d1 As Double
)

public:
void Transparency(
	double d1
)

member Transparency : 
        d1 : float -> unit