The present disclosure is directed toward solutions, transparent films prepared from aromatic copolyamides, and a display element, an optical element or an illumination element using the solutions and/or the films. The copolyamides, which contain pendant carboxylic groups are solution cast into films using cresol, xylene, N,N-dimethylacetamide (DMAc), N-methyl-2-pyrrolidinone (NMP), dimethylsulfoxide (DMSO), or butyl cellosolve or other solvents or mixed solvent which has more than two solvents. When the films are thermally cured at temperatures near the copolymer glass transition temperature, after curing, the polymer films display transmittances >80% from 400 to 750 nm, have coefficients of thermal expansion of less than 20 ppm, and are solvent resistant.