This work describes an experiment in which a pressure sensitive paint (PSP) was used to investigate and measure the pressure distribution on tubercle airfoils in transonic flow. The experiment was conducted in a transonic wind tunnel at Reynolds number of one million, Mach number from 0.6 to 0.8, and angle of attack varying from 0 to 4 degrees. Two PSP images are simultaneously registered by a color high-speed camera acquiring information from the two luminophores sensors present in the Binary PSP. Two sets of airfoil were used: NACA0012 as the baseline and a wavy leading edge NACA0012. The models were manufactured using a 3D rapid prototyping which significantly improved time and cost comparing to conventional manufacture methods, and also the feasibility of such complex wavy leading edge airfoil. The effect of tubercles was well observed due to the high spatial resolution of the PSP. The pressure distribution is clearly seen as a sinusoidal pattern near the leading edge. For some cases, the shock wave strength became weaker. At a specific condition where a possibly shock-lambda was formed for smooth configuration, the tubercle wing suppressed its formation. Possible due to a vortex formed in the tubercle valley then suppressing flow separation, thus avoiding shock-lambda formation.