Hi, Judi, good question! According to the Plaid website: “Although Martha Stewart Sea Glass Paint is water-based and non-toxic, it is always best to allow a “lip line” of ⅘” or 2 cm from the rim of a drinking glass. It is also important not to apply the paint where it will make contact with food.” – so just start a bit lower! If you do the drip line, that can serve as a border so that it looks good.