Enamel paints work on glass as well as on other smooth or shiny surfaces like metal or ceramics. Choose opaque or transparent enamels; transparent makes the piece look like solid-colored glass, but the color will change when you put different-colored liquids or items inside.il-or solvent-based paints are not as popular for glass as other types of paints, but if you like working in oils, you may prefer them. Colors are either transparent or opaque, and they may appear vibrant and high gloss.