Opal effect Polycarbonate Twinwall Roofing Sheet 2m x 690mm. Axiome A® glazing sheets provide a lightweight & robust solution that can be used in many roofing & glazing applications. Axiome A® sheets are easy to cut to size using a fine tooth blade. Opal tint sheets offer heat reduction properties & a privacy effect. Manufactured as a bright white tint the Opal Axiome A® option will reflect heat from the suna€™s rays reducing heat build-up by around 35% of the solar energy.