Irradiation of poly(methylmethacrylate) film, PMMA, with e‐beam, H+, x ray, and deep UV creates reactive centers which combine with acrylic acid vapor to form graft and/or block copolymers with solubilities different from that of PMMA. Dissolution rate studies of modified PMMA using a variety of solvents have revealed that while toluene forms good negative‐tone images, it develops too slowly, and that a mixture of methylisobutylketone and isopropanol is not selective enough to give images with good contrast. Consideration of the solubility parameters of pure PMMA and pure poly(acrylic acid) (PAA) indicates that organic esters such as methylformate (MF), ethylacetate (EA), and a commercially available mixture (Dupont Co.) of dimethylsuccinate, dimethylglutarate, and dimethyladipate (DBE) could be useful development solvents for the samples under discussion. The data obtained reveal that toluene gives the best image, but also reveal that the dissolution rates decrease as the development fronts proceed into the body of the film.