Advances in phototackification

A direct single-layer negative-working phototackification system with application to 4-color half-tone proofing has been invented. It makes use of chemical amplification and is based on photo-induced microphase separation in an initially non-tacky miscible blend of acid-labile and tacky polymers. Factors which influence tack generation are discussed. The system has been sensitized both in the UV for conventional analog proofing and in the near-IR for digital proofing.