An imaging system based upon the peel apart procedure has been described elsewhere. The imaging structure consists of a photochemically active layer comprising a polymer and a photosensitive material such as an azide compound, a thin metal layer deposited on a substrate and a cover film. After imagewise exposure and following heating, peeling of the cover film off the base forms a metal pattern on the base film. In this paper, characteristics of a negative working type structure which used 1, 4-naphthoquinone and vinylchloride-vinylacetate-maleic acid terpolymer (P-VCVAcMAc) was studied by changing various process conditions and the results were compared with the positive working case in which azide compounds and polyvinyl chloride were used. It was found that the image could not be formed if heated after exposure at a temperature above 50°C or if stored longer than a day in the negative working design. In the positive working system, good metal images were obtained with surface-cleaned aluminum layers as well as with untreated ones. In the negative type imaging, however, images were not developed by use of the cleaned surfaces. These results were explained in terms of changes in the peeling strength between the photosensitive polymer layer and the aluminum sheet subjected to the surface treatments. It was suggested that reduction of adhesive strength by surface contamination must be helping the image formation. Surface inspections of aluminum sheets indicated that the surface became much planer by electropolishing. From results of contact angle measurements, it was considered that fresh and clean oxidized layer appeared on the aluminum surface by this treatment. A possible explanation of imaging mechanism was proposed that in the positive type imaging the hydrogen bonds at the metal/photosensitive polymer layer interface are newly formed by polar photolytic products, whereas in the negative type imaging hydrogen bonds at the same interface are destroyed by photochemical products.