Test Pattern explored the luminous properties of sheets of tinted polypropylene when they are layered adjacent to each other and back-lit. The work was comprised of sixteen individual frames that housed four layers of plastic sheet. The two inner layers were cut out as squares of various sizes which create a series of softly focused yet striking colour contrasts and harmonies. The work exposed a range of possible combinations of colour mixing, from the generation of the ephemeral and indistinct boundaries that can be achieved between blues, yellows and greens to the vibrant pulsations made apparent between red, pink, purple and orange and the mixing of soft pastel greys, achieved by overlapping of complimentary colours in the right balance. The final installation produced not only a powerful source of harmonic colour contrasts and dazzling optical affects when looked at directly, but also generated a plethora of colour shadow effects as the spectral light projected ghostly umbras, penumbras and antumbras.