I'm posting this just for reference; a technique for treating raw PET with potassium hydroxide to roughen its surface texture and thus create a hydrophillic subbing. Umut came across it.

Translated from Fiziko-Khimicheskaya Mekhanika Materialov, Vol. 12, No. 2, pp. 118–120, March–April, 1976. By I. Astrina, S. V. Vlasov, R. D. Gorak, Yu. V. Moiseev and Ya. A. Serednitskii